Apparatuses and methods for performing logical operations using sensing circuitry

ABSTRACT

The present disclosure includes apparatuses and methods related to performing logical operations using sensing circuitry. An example apparatus comprises an array of memory cells and sensing circuitry coupled to the array. The sensing circuitry includes a sense amplifier coupled to a pair of complementary sense lines, and a compute component coupled to the sense amplifier. The compute component includes a dynamic latch. The sensing circuitry is configured to perform a logical operation and initially store the result in the sense amplifier.

PRIORITY INFORMATION

This application is a Continuation of U.S. application Ser. No.15/692,003, filed Aug. 31, 2017, which issues as U.S. Pat. No.10,210,911 on Feb. 19, 2019, which is a Continuation of U.S. applicationSer. No. 14/725,956, filed May 29, 2015, which issued as U.S. Pat. No.9,786,335 on Oct. 10, 2017, which claims the benefit of U.S. ProvisionalApplication No. 62/008,023, filed Jun. 5, 2014, the contents of whichare incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to semiconductor memory andmethods, and more particularly, to apparatuses and methods related toperforming logical operations using sensing circuitry.

BACKGROUND

Memory devices are typically provided as internal, semiconductor,integrated circuits in computers or other electronic systems. There aremany different types of memory including volatile and non-volatilememory. Volatile memory can require power to maintain its data (e.g.,host data, error data, etc.) and includes random access memory (RAM),dynamic random access memory (DRAM), static random access memory (SRAM),synchronous dynamic random access memory (SDRAM), and thyristor randomaccess memory (TRAM), among others. Non-volatile memory can providepersistent data by retaining stored data when not powered and caninclude NAND flash memory, NOR flash memory, and resistance variablememory such as phase change random access memory (PCRAM), resistiverandom access memory (RRAM), and magnetoresistive random access memory(MRAM), such as spin torque transfer random access memory (STT RAM),among others.

Electronic systems often include a number of processing resources (e.g.,one or more processors), which may retrieve and execute instructions andstore the results of the executed instructions to a suitable location. Aprocessor can comprise a number of functional units such as arithmeticlogic unit (ALU) circuitry, floating point unit (FPU) circuitry, and/ora combinatorial logic block, for example, which can be used to executeinstructions by performing logical operations such as AND, OR, NOT,NAND, NOR, and XOR, and invert (e.g., inversion) logical operations ondata (e.g., one or more operands). For example, functional unitcircuitry (FUC) may be used to perform arithmetic operations such asaddition, subtraction, multiplication, and/or division on operands via anumber of logical operations.

A number of components in an electronic system may be involved inproviding instructions to the FUC for execution. The instructions may begenerated, for instance, by a processing resource such as a controllerand/or host processor. Data (e.g., the operands on which theinstructions will be executed) may be stored in a memory array that isaccessible by the FUC. The instructions and/or data may be retrievedfrom the memory array and sequenced and/or buffered before the FUCbegins to execute instructions on the data. Furthermore, as differenttypes of operations may be executed in one or multiple clock cyclesthrough the FUC, intermediate results of the instructions and/or datamay also be sequenced and/or buffered.

In many instances, the processing resources (e.g., processor and/orassociated FUC) may be external to the memory array, and data isaccessed via a bus between the processing resources and the memory arrayto execute a set of instructions. Processing performance may be improvedin a processor-in-memory (PIM) device, in which a processor may beimplemented internal and/or near to a memory (e.g., directly on a samechip as the memory array), which may conserve time and power inprocessing. However, such PIM devices may have various drawbacks such asan increased chip size. Moreover, such PIM devices may still consumeundesirable amounts of power in association with performing logicaloperations (e.g., compute functions).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an apparatus in the form of a computingsystem including a memory device in accordance with a number ofembodiments of the present disclosure.

FIG. 2 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 3 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 4 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 5 is a schematic diagram illustrating a portion of sensingcircuitry in accordance with a number of embodiments of the presentdisclosure.

FIG. 6 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 7 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 8 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 9 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 10 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 11 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 12 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 13 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

FIG. 14 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 15 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 16 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 17 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure.

FIG. 18 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure.

DETAILED DESCRIPTION

The present disclosure includes apparatuses and methods related toperforming logical operations using sensing circuitry. An exampleapparatus comprises an array of memory cells and sensing circuitrycoupled to the array. The sensing circuitry includes a sense amplifiercoupled to a pair of complementary sense lines, and a compute componentcoupled to the sense amplifier. The compute component includes a dynamiclatch. The sensing circuitry is configured to perform a logicaloperation and initially store the result in the sense amplifier.

A number of embodiments of the present disclosure can provide improvedparallelism and/or reduced power consumption in association withperforming compute functions as compared to previous systems such asprevious PIM systems and systems having an external processor (e.g., aprocessing resource located external from a memory array, such as on aseparate integrated circuit chip). For instance, a number of embodimentscan provide for performing fully complete compute functions such asinteger add, subtract, multiply, divide, and CAM (content addressablememory) functions without transferring data out of the memory array andsensing circuitry via a bus (e.g., data bus, address bus, control bus),for instance. Such compute functions can involve performing a number oflogical operations (e.g., logical functions such as AND, OR, NOT, NOR,NAND, XOR, etc.). However, embodiments are not limited to theseexamples. For instance, performing logical operations can includeperforming a number of non-Boolean logic operations such as copy,compare, destroy, etc.

In previous approaches, data may be transferred from the array andsensing circuitry (e.g., via a bus comprising input/output (I/O) lines)to a processing resource such as a processor, microprocessor, and/orcompute engine, which may comprise ALU circuitry and/or other functionalunit circuitry configured to perform the appropriate logical operations.However, transferring data from a memory array and sensing circuitry tosuch processing resource(s) can involve significant power consumption.Even if the processing resource is located on a same chip as the memoryarray, significant power can be consumed in moving data out of the arrayto the compute circuitry, which can involve performing a sense line(which may be referred to herein as a digit line or data line) addressaccess (e.g., firing of a column decode signal) in order to transferdata from sense lines onto I/O lines (e.g., local I/O lines), moving thedata to the array periphery, and providing the data to the computefunction.

Furthermore, the circuitry of the processing resource(s) (e.g., computeengine) may not conform to pitch rules associated with a memory array.For example, the cells of a memory array may have a 4F² or 6F² cellsize, where “F” is a feature size corresponding to the cells. As such,the devices (e.g., logic gates) associated with ALU circuitry ofprevious PIM systems may not be capable of being formed on pitch withthe memory cells, which can affect chip size and/or memory density, forexample. A number of embodiments of the present disclosure includesensing circuitry formed on pitch with memory cells of the array andcapable of performing compute functions such as those described hereinbelow.

In the following detailed description of the present disclosure,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration how one or more embodimentsof the disclosure may be practiced. These embodiments are described insufficient detail to enable those of ordinary skill in the art topractice the embodiments of this disclosure, and it is to be understoodthat other embodiments may be utilized and that process, electrical,and/or structural changes may be made without departing from the scopeof the present disclosure. As used herein, the designator “N,”particularly with respect to reference numerals in the drawings,indicates that a number of the particular feature so designated can beincluded. As used herein, “a number of” a particular thing can refer toone or more of such things (e.g., a number of memory arrays can refer toone or more memory arrays).

The figures herein follow a numbering convention in which the firstdigit or digits correspond to the drawing figure number and theremaining digits identify an element or component in the drawing.Similar elements or components between different figures may beidentified by the use of similar digits. For example, 206 may referenceelement “06” in FIG. 2, and a similar element may be referenced as 606in FIG. 6. As will be appreciated, elements shown in the variousembodiments herein can be added, exchanged, and/or eliminated so as toprovide a number of additional embodiments of the present disclosure. Inaddition, as will be appreciated, the proportion and the relative scaleof the elements provided in the figures are intended to illustratecertain embodiments of the present invention, and should not be taken ina limiting sense.

FIG. 1 is a block diagram of an apparatus in the form of a computingsystem 100 including a memory device 120 in accordance with a number ofembodiments of the present disclosure. As used herein, a memory device120, a memory array 130, and/or sensing circuitry 150 might also beseparately considered an “apparatus.”

System 100 includes a host 110 coupled (e.g., connected) to memorydevice 120, which includes a memory array 130. Host 110 can be a hostsystem such as a personal laptop computer, a desktop computer, a digitalcamera, a smart phone, or a memory card reader, among various othertypes of hosts. Host 110 can include a system motherboard and/orbackplane and can include a number of processing resources (e.g., one ormore processors, microprocessors, or some other type of controllingcircuitry). The system 100 can include separate integrated circuits orboth the host 110 and the memory device 120 can be on the sameintegrated circuit. The system 100 can be, for instance, a server systemand/or a high performance computing (HPC) system and/or a portionthereof. Although the example shown in FIG. 1 illustrates a systemhaving a Von Neumann architecture, embodiments of the present disclosurecan be implemented in non-Von Neumann architectures (e.g., a Turingmachine), which may not include one or more components (e.g., CPU, ALU,etc.) often associated with a Von Neumann architecture.

For clarity, the system 100 has been simplified to focus on featureswith particular relevance to the present disclosure. The memory array130 can be a DRAM array, SRAM array, STT RAM array, PCRAM array, TRAMarray, RRAM array, NAND flash array, and/or NOR flash array, forinstance. The array 130 can comprise memory cells arranged in rowscoupled by access lines (which may be referred to herein as word linesor select lines) and columns coupled by sense lines. Although a singlearray 130 is shown in FIG. 1, embodiments are not so limited. Forinstance, memory device 120 may include a number of arrays 130 (e.g., anumber of banks of DRAM cells). An example DRAM array is described inassociation with FIG. 2.

The memory device 120 includes address circuitry 142 to latch addresssignals provided over an I/O bus 156 (e.g., a data bus) through I/Ocircuitry 144. Address signals are received and decoded by a row decoder146 and a column decoder 152 to access the memory array 130. Data can beread from memory array 130 by sensing voltage and/or current changes onthe data lines using sensing circuitry 150. The sensing circuitry 150can read and latch a page (e.g., row) of data from the memory array 130.The I/O circuitry 144 can be used for bi-directional data communicationwith host 110 over the I/O bus 156. The write circuitry 148 is used towrite data to the memory array 130.

Control circuitry 140 decodes signals provided by control bus 154 fromthe host 110. These signals can include chip enable signals, writeenable signals, and address latch signals that are used to controloperations performed on the memory array 130, including data read, datawrite, and data erase operations. In various embodiments, the controlcircuitry 140 is responsible for executing instructions from the host110. The control circuitry 140 can be a state machine, a sequencer, orsome other type of controller.

Examples of the sensing circuitry 150 are described further below. Forinstance, in a number of embodiments, the sensing circuitry 150 cancomprise a number of sense amplifiers (e.g., sense amplifier 206 shownin FIG. 2 or sense amplifier 506 shown in FIG. 5) and a number ofcompute components (e.g., compute component 231-1 shown in FIG. 2),which can be used to perform logical operations (e.g., on dataassociated with complementary data lines). The sense amplifier cancomprise a static latch, for example, which can be referred to herein asthe primary latch. The compute component 231-1 can comprise a dynamicand/or static latch, for example, which can be referred to herein as thesecondary latch, and which can serve as, and be referred to as, anaccumulator.

In a number of embodiments, the sensing circuitry (e.g., 150) can beused to perform logical operations using data stored in array 130 asinputs and store the results of the logical operations back to the array130 without transferring data via a sense line address access (e.g.,without firing a column decode signal). As such, various computefunctions can be performed using, and within, sensing circuitry 150rather than (or in association with) being performed by processingresources external to the sensing circuitry (e.g., by a processorassociated with host 110 and/or other processing circuitry, such as ALUcircuitry, located on device 120 (e.g., on control circuitry 140 orelsewhere)).

In various previous approaches, data associated with an operand, forinstance, would be read from memory via sensing circuitry and providedto external ALU circuitry via I/O lines (e.g., via local I/O linesand/or global I/O lines). The external ALU circuitry could include anumber of registers and would perform compute functions using theoperands, and the result would be transferred back to the array via theI/O lines. In contrast, in a number of embodiments of the presentdisclosure, sensing circuitry (e.g., 150) is configured to performlogical operations on data stored in memory (e.g., array 130) and storethe result back to the memory without enabling an I/O line (e.g., alocal I/O line) coupled to the sensing circuitry, which can be formed onpitch with the memory cells of the array. Enabling an I/O line caninclude enabling (e.g., turning on) a transistor having a gate coupledto a decode signal (e.g., a column decode signal) and a source/draincoupled to the I/O line. Embodiments are not so limited. For instance,in a number of embodiments, the sensing circuitry (e.g., 150) can beused to perform logical operations without enabling column decode linesof the array; however, the local I/O line(s) may be enabled in order totransfer a result to a suitable location other than back to the array(e.g., to an external register).

As such, in a number of embodiments, circuitry external to array 130 andsensing circuitry 150 is not needed to perform compute functions as thesensing circuitry 150 can perform the appropriate logical operations toperform such compute functions without the use of an external processingresource. Therefore, the sensing circuitry 150 may be used to complimentand/or to replace, at least to some extent, such an external processingresource (or at least the bandwidth of such an external processingresource). However, in a number of embodiments, the sensing circuitry150 may be used to perform logical operations (e.g., to executeinstructions) in addition to logical operations performed by an externalprocessing resource (e.g., host 110). For instance, host 110 and/orsensing circuitry 150 may be limited to performing only certain logicaloperations and/or a certain number of logical operations.

FIG. 2 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Amemory cell comprises a storage element (e.g., capacitor) and an accessdevice (e.g., transistor). For instance, transistor 202-1 and capacitor203-1 comprises a memory cell, and transistor 202-2 and capacitor 203-2comprises a memory cell, etc. In this example, the memory array 230 is aDRAM array of 1T1C (one transistor one capacitor) memory cells. In anumber of embodiments, the memory cells may be destructive read memorycells (e.g., reading the data stored in the cell destroys the data suchthat the data originally stored in the cell is refreshed after beingread). The cells of the memory array 230 are arranged in rows coupled byword lines 204-X (Row X), 204-Y (Row Y), etc., and columns coupled bypairs of complementary data lines DIGIT(n−1)/DIGIT(n−1)_,DIGIT(n)/DIGIT(n)_, DIGIT(n+1)/DIGIT(n+1)_. The individual data linescorresponding to each pair of complementary data lines can also bereferred to as data lines 205-1 (D) and 205-2 (D_) respectively.Although only three pair of complementary data lines are shown in FIG.2, embodiments of the present disclosure are not so limited, and anarray of memory cells can include additional columns of memory cellsand/or data lines (e.g., 4,096, 8,192, 16,384, etc.).

Memory cells can be coupled to different data lines and/or word lines.For example, a first source/drain region of a transistor 202-1 can becoupled to data line 205-1 (D), a second source/drain region oftransistor 202-1 can be coupled to capacitor 203-1, and a gate of atransistor 202-1 can be coupled to word line 204-X. A first source/drainregion of a transistor 202-2 can be coupled to data line 205-2 (D_), asecond source/drain region of transistor 202-2 can be coupled tocapacitor 203-2, and a gate of a transistor 202-2 can be coupled to wordline 204-Y. The cell plate, as shown in FIG. 2, can be coupled to eachof capacitors 203-1 and 203-2. The cell plate can be a common node towhich a reference voltage (e.g., ground) can be applied in variousmemory array configurations.

The memory array 230 is coupled to sensing circuitry 250 in accordancewith a number of embodiments of the present disclosure. In this example,the sensing circuitry 250 comprises a sense amplifier 206 and a computecomponent 231-1 corresponding to respective columns of memory cells(e.g., coupled to respective pairs of complementary data lines). Thesensing circuitry 250 can correspond to sensing circuitry 150 shown inFIG. 1, for example. The sense amplifier 206 can be a sense amplifiersuch as sense amplifier 506 described below in association with FIG. 5.The sense amplifier 206 can be operated to determine a data value (e.g.,logic state) stored in a selected memory cell. The sense amplifier 206can comprise a cross coupled latch, which can be referred to herein as aprimary latch. Embodiments are not limited to the example senseamplifier 206. As an example, the sense amplifier 206 can becurrent-mode sense amplifier and/or single-ended sense amplifier (e.g.,sense amplifier coupled to one data line). Also, embodiments of thepresent disclosure are not limited to a folded data line architecturesuch as that shown in FIG. 2.

As described further below, in a number of embodiments, the sensingcircuitry (e.g., sense amplifier 206 and compute component 231) can beoperated to perform a logical operation using a dynamic latch of thecompute component 231-1 and store the result in the sense amplifier 206without transferring data from the sensing circuitry via an I/O line(e.g., without performing a data line address access via activation of acolumn decode signal, for instance).

As used herein, a dynamic latch refers to a latch that relies oncapacitance of transistors (e.g., gates) or other structures to maintaina particular data state stored as voltages on output nodes. A dynamiclatch can be set/reset by selectively charging/discharging thecapacitance. As such, the data state stored as voltages on the outputnodes of the dynamic latch may remain valid only for a certain period oftime. In contrast, a latch other than a dynamic latch (e.g., a staticlatch such as a cross-coupled latch) can retain its output level as longas power is provided and therefore can be stable over long periods oftime. A dynamic latch can operate faster, consume less power, and/or beof smaller physical size compared to a static latch. One reason using adynamic latch in the sensing circuitry 250 consumes less power thanprevious approaches is because loading the dynamic latch of the computecomponent 231-1 does not necessitate “overpowering” a cross-coupledlatch (e.g., a “jam latch”).

According to various embodiments of the present disclosure, a dynamiclatch is used in an accumulator in performing logical operations inassociation with a sense amplifier (“sense amp”). The sense amplifierand accumulator are configured to have a result of the logical operationbe initially stored in the sense amp. A data value (which may, or maynot, be used in the logical operation) can remain unchanged in theaccumulator. Benefits of having a logical operation result initiallystored in a sense amplifier rather than the accumulator are discussedfurther below.

Performance of logical operations (e.g., Boolean logical functionsinvolving data values) is fundamental and commonly used. Boolean logicfunctions are used in many higher level functions. Consequently, speedand/or power efficiencies that can be realized with improved logicaloperations, which can translate into speed and/or power efficiencies ofhigher order functionalities. Described herein are apparatuses andmethods for performing logical operations without transferring data viaan input/output (I/O) line and/or without transferring data to a controlcomponent external to the array. Depending on memory array architecture,the apparatuses and methods for performing the logical operations maynot require amplification of a sense line (e.g., data line, digit line,bit line) pair.

As shown in FIG. 2, the sense amplifier 206 and the compute component231-1 can be coupled to the array 230 via shift circuitry 223. In thisexample, the shift circuitry 223 comprises a pair of isolation devices221-1 and 221-2 (e.g., isolation transistors 221-1 and 221-2) coupled todata lines 205-1 (D) and 205-2 (D_), respectively). The isolationtransistors 221-1 and 221-2 are coupled to a control signal 222 (NORM)that, when activated, enables (e.g., turns on) the isolation transistors221-1 and 221-2 to couple the corresponding sense amplifier 206 andcompute component 231-1 to a corresponding column of memory cells (e.g.,to a corresponding pair of complementary data lines 205-1 (D) and 205-2(D_)). According to various embodiments, conduction of isolationtransistors 221-1 and 221-2 can be referred to as a “normal”configuration of the shift circuitry 223.

In the example illustrated in FIG. 2, the shift circuitry 223 includesanother (e.g., a second) pair of isolation devices (e.g., transistors221-3 and 221-4) coupled to a complementary control signal 219 (SHIFT),which can be activated, for example, when NORM is deactivated. Theisolation transistors 221-3 and 221-4 can be operated (e.g., via controlsignal 219) such that a particular sense amplifier 206 and computecomponent 231-1 are coupled to a different pair of complementary datalines (e.g., a pair of complementary data lines different than the pairof complementary data lines to which isolation transistors 221-1 and221-2 couple the particular sense amplifier 206 and compute component231), or can couple a particular sense amplifier 206 and computecomponent 231-1 to another memory array (and isolate the particularsense amplifier 206 and compute component 231-1 from a first memoryarray). According to various embodiments, the shift circuitry 223 can bearranged as a portion of (e.g., within) the sense amplifier 206, forinstance.

Although the shift circuitry 223 shown in FIG. 2 includes isolationtransistors 221-1 and 221-2 used to couple particular sensing circuitry250 (e.g., a particular sense amplifier 206 and corresponding computecomponent 231) to a particular pair of complementary data lines 205-1(D) and 205-2 (D_) (e.g., DIGIT(n) and DIGIT(n)_) and isolationtransistors 221-3 and 221-4 are arranged to couple the particularsensing circuitry 250 to an adjacent pair of complementary data lines inone particular direction (e.g., adjacent data lines DIGIT(n+1) andDIGIT(n+1)_ shown to the right in FIG. 2), embodiments of the presentdisclosure are not so limited. For instance, shift circuitry can includeisolation transistors 221-1 and 221-2 used to couple particular sensingcircuitry to a particular pair of complementary data lines (e.g.,DIGIT(n) and DIGIT(n) and isolation transistors 221-3 and 221-4 arrangedso as to be used to couple the particular sensing circuitry to anadjacent pair of complementary data lines in another particulardirection (e.g., adjacent data lines DIGIT(n−1) and DIGIT(n−1)_ shown tothe left in FIG. 2).

Embodiments of the present disclosure are not limited to theconfiguration of shift circuitry 223 shown in FIG. 2. Also, embodimentsof the present disclosure can be configured as otherwise shown in FIG. 2but without the shift circuitry 223. That is, shift circuitry 223 isoptional. In a number of embodiments, shift circuitry such as that shownin FIG. 2 can be operated (e.g., in conjunction with sense amplifiers206 and compute components 231) in association with performing computefunctions such as adding and subtracting functions without transferringdata out of the sensing circuitry 250 via an I/O line (e.g., local I/Oline 201 (IO/IO_), for instance.

Although shown in FIG. 1 but not shown in FIG. 2, each column of memorycells can be coupled to a column decode line that can be enabled totransfer, via local I/O line 201, a data value from a correspondingsense amplifier 206 and/or compute component 231-1 to a controlcomponent external to the array such as an external processing resource(e.g., host processor and/or other functional unit circuitry). Thecolumn decode line can be coupled to a column decoder (e.g., columndecoder 152 shown in FIG. 1). However, as described herein, in a numberof embodiments, data need not be transferred via such I/O lines (e.g.,I/O line 201) to perform logical operations in accordance withembodiments of the present disclosure. In a number of embodiments, shiftcircuitry such as that shown in FIG. 2 can be operated (e.g., inconjunction with sense amplifiers 206 and compute components 231) inperforming compute functions such as adding and subtracting functionswithout transferring data to a control component external to the array,for instance.

In the example illustrated in FIG. 2, the compute component 231-1includes eight transistors (e.g., four transistors per complementarydata line). The transistors are formed on pitch with the sense amplifier206 and with the memory cells of the array 230. The compute component231-1 comprises a dynamic latch that can be referred to as a secondarylatch, which can operate as (e.g., serve as) an accumulator inperforming logical operations. As such, the secondary latch of thecompute component 231-1 may be referred to as the accumulator of thecompute component 231-1. The compute component 231-1 is coupled to thesense amplifier 206 via the data lines 205-1 (D) and D_205-2 as shown inFIG. 2. In this example, the transistors of compute component 231-1 areall n-channel transistors (e.g., NMOS transistors); however, embodimentsare not so limited.

In this example, the compute component 231-1 includes a first passtransistor 207-1 having a first source/drain region directly coupled(e.g., connected) to data line 205-1 (D), which is also directly coupledto a first source/drain region of a load transistor 218-2 and a firstsource/drain region of an invert transistor 214-2. As used herein,“directly coupled” intends coupled without an intervening component. Asecond pass transistor 207-2 has a first source/drain region directlycoupled to data line 205-2, which is also directly coupled to a firstsource/drain region of a load transistor 218-1 and a first source/drainregion of an invert transistor 214-1.

The gates of load transistors 218-1 and 218-2 are commonly coupledtogether and to a LOAD control signal. A second source/drain region ofload transistor 218-1 is directly coupled to a gate of transistor 209-1(e.g., “dynamic latch transistor”) at a common node of the latch (e.g.,node S1 of the dynamic latch). A second source/drain region of loadtransistor 218-2 is directly coupled to a gate of transistor 209-2 atthe complementary common node of the latch (e.g., node S2 of the dynamiclatch).

A second source/drain region of inverting transistor 214-1 is directlycoupled to a first source/drain region of transistor 209-1 and to asecond source/drain region of pass transistor 207-1. A secondsource/drain region of inverting transistor 214-2 is directly coupled toa first source/drain region of transistor 209-2 and to a secondsource/drain region of pass transistor 207-2. A second source/drainregion of transistors 209-1 and 209-2 are commonly coupled to areference signal (e.g., ground (GND)). A gate of pass transistor 207-1is coupled to a control signal AND. A gate of pass transistor 207-2 iscoupled to a control signal OR. A gate of invert transistor 214-1 iscoupled to a control signal ORinv. A gate of invert transistor 214-2 iscoupled to a control signal ANDinv.

The dynamic latch of compute component 231-1 shown in FIG. 2 can operateas an accumulator (and may be referred to as such) storing datadynamically on nodes S1 and S2. Activating the LOAD control signalenables load transistors 218-1 and 218-2 (e.g., causes them to conduct)and thereby loads complementary data onto nodes S1 and S2, when loadtransistors 218-1 and 218-2 are conducting (e.g., enabled via the LOADcontrol signal). Note however that the voltage on data line 205-2 (D_)is coupled to node S1 and the voltage on data line 205-1 (D) is coupledto node S2. The LOAD control signal can be elevated to a voltage greaterthan V_(DD) to pass a full V_(DD) level to nodes S1/S2. However,elevating the LOAD control signal to a voltage greater than V_(DD) isoptional, and functionality of the circuit shown in FIG. 2 is notcontingent on the LOAD control signal being elevated to a voltagegreater than V_(DD).

The sensing circuitry 250 is configured to perform logical operations ondata values stored in the array of memory cells with the result (e.g.,resultant data value) being stored (e.g., residing) in the senseamplifier (e.g., 206). The logical operations (e.g., AND, OR, etc.) canbe performed on data values stored in cells coupled to different accesslines (e.g., Row X and Row Y) and to one or more pairs of complementarydata lines (e.g., 205-1 and 205-2).

Operation of the sensing circuitry 250 to perform AND, OR, and NOT(e.g., invert) operations is described further below, as is operation ofthe shift circuitry 223 to accomplish a SHIFT between pairs ofcomplementary data lines. While operations are described below involvingone or two data values, logical operations involving a plurality of datavalues can be accomplished without having to transfer data to anexternal arithmetic logic unit (ALU) or other processing resourceoutside of the sensing circuitry 250, which may only operate on32/64/128 bits at a time. For example, assuming 32 word lines and 16 Kdata lines (e.g., bit lines), logical operations involving 16 K ANDs/ORsof 32-bit data values can be implemented utilizing the sensing circuitryassociated with a plurality of data lines without transferring data outof the sensing circuitry.

The functionality of the sensing circuitry of FIG. 2 is described belowand summarized in Table 1 below. Initially storing the result of aparticular logical operation in the sense amplifier (e.g., in a primarylatch of sense amplifier 206) can provide improved versatility ascompared to previous approaches in which the result may initially residein a secondary latch (e.g., accumulator) of a compute component (e.g.,231-1), and then be subsequently transferred to the sense amp, forinstance.

TABLE 1 Operation Accumulator Sense Amp AND Unchanged Result ORUnchanged Result NOT Unchanged Result SHIFT Unchanged Shifted Data

Initially storing the result of a particular operation in the senseamplifier (e.g., without having to perform an additional operation tomove the result from the accumulator to the sense amp) is advantageousbecause, for instance, the result can be written to a row (of the arrayof memory cells) or back into the accumulator without performing aprecharge cycle (e.g., on the complementary data lines 205-1 (D) and/or205-2 (D_)). A precharge cycle can involve precharging complementarydata lines to a predetermined voltage level (e.g., V_(DD)/2)before/after performing an operation using the complementary data lines.Reducing the number of precharge cycles can increase the speed of and/orreduce the power associated with performing various operations. As anexample, in association with performing an AND operation on a pair ofdata values, the sensing circuitry shown in FIG. 2 consumes power foronly one of the four possible data combinations shown in Table 2 below.For instance, if an AND is performed on a data value residing in theaccumulator of the compute component (e.g., 231-1) and a data valuestored in a memory cell coupled to a particular access line (e.g., RowX), then current (e.g., about 60 mA) is drawn only for the situation inwhich the accumulator stores a “0” and the memory cell stores a “1,” asshown in Table 2.

TABLE 2 Accumulator Row AND Icc 0 0 0 0 0 1 0 Approx. 60 mA 1 0 0 0 1 11 0

Prior to performing a logical operation, an equilibrate operation canoccur such that the complementary data lines D and D_ are shortedtogether at an equilibration voltage (e.g., V_(DD)/2), as is describedin detail with respect to sense amplifier 506 illustrated in FIG. 5. Aninitial operation phase associated with performing an AND or an ORoperation on a first data value and a second data value stored in memorycells coupled to different access lines (e.g., 204-X and 204-Y) caninclude loading the first data value into the accumulator of computecomponent 231-1.

FIG. 3 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure. FIG. 3 illustrates atiming diagram associated with initiating an AND logical operation afterstarting to load the second operand (e.g., Row Y data value) into thesense amplifier. FIG. 3 illustrates the sense amplifier and accumulatorsignals for various combinations of first and second operand datavalues. FIG. 3 shows the respective sense amplifier and accumulatorsignals corresponding to each combination of Row X data value and Row Ydata value in each set. The particular timing diagram signals arediscussed below with respect to the pseudo code associated with an ANDoperation of the circuit shown in FIG. 2.

An example of pseudo code associated with loading (e.g., copying) afirst data value stored in a cell coupled to row 204-X into theaccumulator can be summarized as follows:

Copy Row X into the Accumulator:

-   -   Deactivate EQ    -   Open Row X    -   Fire Sense Amps (after which Row X data resides in the sense        amps)    -   Activate LOAD (sense amplifier data (Row X) is transferred to        nodes S1 and S2 of the Accumulator and resides there        dynamically)    -   Deactivate LOAD    -   Close Row X    -   Precharge

In the pseudo code above, “Deactivate EQ” indicates that anequilibration signal (EQ signal shown in FIG. 3) corresponding to thesense amplifier 206 is disabled at t₁ as shown in FIG. 3 (e.g., suchthat the complementary data lines (e.g., 205-1 (D) and 205-2 (D_) are nolonger shorted to V_(DD)/2). After equilibration is deactivated, aselected row (e.g., ROW X) is enabled (e.g., selected, opened such as byactivating a signal to select a particular row) as indicated by “OpenRow X” in the pseudo code and shown at t₂ for signal Row X in FIG. 3.When the voltage signal applied to ROW X reaches the threshold voltage(Vt) of the access transistor (e.g., 202-2) corresponding to theselected cell, the access transistor turns on and couples the data line(e.g., 205-2 (D_)) to the selected cell (e.g., to capacitor 203-2) whichcreates a differential voltage signal between the data lines.

After Row X is opened, in the pseudo code above, “Fire Sense Amps”indicates that the sense amplifier 206 is enabled to set the primarylatch and subsequently disabled. For example, as shown at t₃ in FIG. 3,the ACT positive control signal (e.g., 590 shown in FIG. 5) goes highand the RnIF negative control signal (e.g., 528 shown in FIG. 5) goeslow, which amplifies the differential signal between 205-1 (D) and D_20502, resulting in a voltage (e.g., V_(DD)) corresponding to a logic 1or a voltage (e.g., GND) corresponding to a logic 0 being on data line205-1 (D) (and the voltage corresponding to the other logic state beingon complementary data line 205-2 (D_)). The sensed data value is storedin the primary latch of sense amplifier 206. The primary energyconsumption occurs in charging the data lines (e.g., 205-1 (D) or 205-2(D_)) from the equilibration voltage V_(DD)/2 to the rail voltageV_(DD).

The four sets of possible Sense amplifier and Accumulator signalsillustrated in FIG. 3 (e.g., one for each combination of Row X and Row Ydata values) shows the behavior of signals on data lines D and D_. TheRow X data value is stored in the primary latch of the sense amp. Itshould be noted that FIG. 2 shows that the memory cell including storageelement 202-2, corresponding to Row X, is coupled to the complementarydata line D_, while the memory cell including storage element 202-1,corresponding to Row Y, is coupled to data line D. However, as can beseen in FIG. 2, the charge stored in memory cell 202-2 (corresponding toRow X) corresponding to a “0” data value causes the voltage on data lineD_ (to which memory cell 202-2 is coupled) to go high and the chargestored in memory cell 202-2 corresponding to a “1” data value causes thevoltage on data line D_ to go low, which is opposite correspondencebetween data states and charge stored in memory cell 202-2,corresponding to Row Y, that is coupled to data line D. Thesedifferences in storing charge in memory cells coupled to different datalines is appropriately accounted for when writing data values to therespective memory cells.

After firing the sense amps, in the pseudo code above, “Activate LOAD”indicates that the LOAD control signal goes high as shown at t₄ in FIG.3, causing load transistors 218-1 and 218-2 to conduct. In this manner,activating the LOAD control signal enables the dynamic latch (e.g.,secondary latch in the accumulator) of the compute component 23-1. Thesensed data value stored in the sense amplifier 206 is transferred(e.g., copied) to the dynamic latch so as to be dynamically stored onnodes S1 and S2. As shown for each of the four sets of possible Senseamplifier and Accumulator signals illustrated in FIG. 3, the behavior atS1 and S2 of the dynamic latch of the Accumulator indicates thesecondary latch is loaded with the Row X data value. As shown in FIG. 3,the dynamic latch of the Accumulator may flip (e.g., see Accumulatorsignals for Row X=“0” and Row Y=“0” and for Row X=“1” and Row Y=“0”), ornot flip (e.g., see Accumulator signals for Row X=“0” and Row Y=“1” andfor Row X=“1” and Row Y=“1”), depending on the data value previouslystored in the dynamic latch.

After setting the dynamic latch from the data values stored in the senseamplifier (and present on the data lines 205-1 (D) and 205-2 (D_), inthe pseudo code above, “Deactivate LOAD” indicates that the LOAD controlsignal goes back low as shown at t₅ in FIG. 3 to cause the loadtransistors 218-1 and 218-2 to stop conducting and thereby isolate thedynamic latch from the complementary data lines. However, the data valueremains dynamically stored in dynamic latch of the accumulator at nodesS1 and S2.

After storing the data value on the dynamic latch, the selected row(e.g., ROW X) is disabled (e.g., deselected, closed such as bydeactivating a select signal for a particular row) as indicated by“Close Row X” and indicated at t₆ in FIG. 3, which can be accomplishedby the access transistor turning off to decouple the selected cell fromthe corresponding data line. Once the selected row is closed and thememory cell is isolated from the data lines, the data lines can beprecharged as indicated by the “Precharge” in the pseudo code above. Aprecharge of the data lines can be accomplished by an equilibrateoperation, as described above and shown in FIG. 3 by the EQ signal goinghigh at t₇. As shown in each of the four sets of possible Senseamplifier and Accumulator signals illustrated in FIG. 3 at t₇, theequilibrate operation causes the voltage on data lines D and D_ to eachreturn to V_(DD)/2. Equilibration can occur, for instance, prior to amemory cell sensing operation or the logical operations (describedbelow).

A subsequent operation phase associated with performing the AND or theOR operation on the first data value (now stored in the sense amplifier206 and the dynamic latch of the accumulator 231-1) and the second datavalue (stored in a memory cell 202-1 coupled to Row Y 204-Y) includesperforming particular steps which depend on the whether an AND or an ORis to be performed. Examples of pseudo code associated with “ANDing” and“ORing” the data value residing in the accumulator (e.g., the first datavalue stored in the memory cell 202-2 coupled to Row X 204-X) and thesecond data value (e.g., the data value stored in the memory cell 202-1coupled to Row Y 204-Y) are summarized below. Example pseudo codeassociated with “ANDing” the data values can include:

Deactivate EQ

Open Row Y

Fire Sense Amps (after which Row Y data resides in the sense amps)

Close Row Y

-   -   The result of the logic operation, in the next operation, will        be placed on the sense amp, which will overwrite any row that is        open.    -   Even when Row Y is closed, the sense amplifier still contains        the Row Y data value.

Activate AND

-   -   This results in the sense amplifier being written to the value        of the function (e.g., Row X AND Row Y)    -   If the accumulator contains a “0” (i.e., a voltage corresponding        to a “0” on node S2 and a voltage corresponding to a “1” on node        S1), the sense amplifier data is written to a “0”    -   If the accumulator contains a “1” (i.e., a voltage corresponding        to a “1” on node S2 and a voltage corresponding to a “0” on node        S1), the sense amplifier data remains unchanged (Row Y data)    -   This operation leaves the data in the accumulator unchanged.

Deactivate AND

Precharge

In the pseudo code above, “Deactivate EQ” indicates that anequilibration signal corresponding to the sense amplifier 206 isdisabled (e.g., such that the complementary data lines 205-1 (D) and205-2 (D_) are no longer shorted to V_(DD)/2), which is illustrated inFIG. 3 at t₈. After equilibration is deactivated, a selected row (e.g.,ROW Y) is enabled as indicated in the pseudo code above by “Open Row Y”and shown in FIG. 3 at t₉. When the voltage signal applied to ROW Yreaches the threshold voltage (Vt) of the access transistor (e.g.,202-1) corresponding to the selected cell, the access transistor turnson and couples the data line (e.g., D_ 205-1) to the selected cell(e.g., to capacitor 203-1) which creates a differential voltage signalbetween the data lines.

After Row Y is opened, in the pseudo code above, “Fire Sense Amps”indicates that the sense amplifier 206 is enabled to amplify thedifferential signal between 205-1 (D) and 205-2 (D_), resulting in avoltage (e.g., V_(DD)) corresponding to a logic 1 or a voltage (e.g.,GND) corresponding to a logic 0 being on data line 205-1 (D) (and thevoltage corresponding to the other logic state being on complementarydata line 205-2 (D_)). As shown at t₁₀ in FIG. 3, the ACT positivecontrol signal (e.g., 590 shown in FIG. 5) goes high and the RnIFnegative control signal (e.g., 528 shown in FIG. 5) goes low to fire thesense amps. The sensed data value from memory cell 202-1 is stored inthe primary latch of sense amplifier 206, as previously described. Thedynamic latch still corresponds to the data value from memory cell 202-2since the dynamic latch is unchanged.

After the second data value sensed from the memory cell 202-1 coupled toRow Y is stored in the primary latch of sense amplifier 206, in thepseudo code above, “Close Row Y” indicates that the selected row (e.g.,ROW Y) can be disabled if it is not desired to store the result of theAND logical operation back in the memory cell corresponding to Row Y.However, FIG. 3 shows that Row Y is left open such that the result ofthe logical operation can be stored back in the memory cellcorresponding to Row Y. Isolating the memory cell corresponding to Row Ycan be accomplished by the access transistor turning off to decouple theselected cell 202-1 from the data line 205-1 (D). After the selected RowY is configured (e.g., to isolate the memory cell or not isolate thememory cell), “Activate AND” in the pseudo code above indicates that theAND control signal goes high as shown in FIG. 3 at t₁₁, causing passtransistor 207-1 to conduct. In this manner, activating the AND controlsignal causes the value of the function (e.g., Row X AND Row Y) to bewritten to the sense amp.

With the first data value (e.g., Row X) stored in the dynamic latch ofthe accumulator 231-1 and the second data value (e.g., Row Y) stored inthe sense amplifier 206, if the dynamic latch of the accumulator 231-1contains a “0” (i.e., a voltage corresponding to a “0” on node S2 and avoltage corresponding to a “1” on node S1), the sense amplifier data iswritten to a “0” (regardless of the data value previously stored in thesense amp) since the voltage corresponding to a “1” on node S1 causestransistor 209-1 to conduct thereby coupling the sense amplifier 206 toground through transistor 209-1, pass transistor 207-1 and data line205-1 (D). When either data value of an AND operation is “0,” the resultis a “0.” Here, when the second data value (in the dynamic latch) is a“0,” the result of the AND operation is a “0” regardless of the state ofthe first data value, and so the configuration of the sensing circuitrycauses the “0” result to be written and initially stored in the senseamplifier 206. This operation leaves the data value in the accumulatorunchanged (e.g., from Row X).

If the dynamic latch of the accumulator contains a “1” (e.g., from RowX), then the result of the AND operation depends on the data valuestored in the sense amplifier 206 (e.g., from Row Y). The result of theAND operation should be a “1” if the data value stored in the senseamplifier 206 (e.g., from Row Y) is also a “1,” but the result of theAND operation should be a “0” if the data value stored in the senseamplifier 206 (e.g., from Row Y) is also a “0.” The sensing circuitry231-1 is configured such that if the dynamic latch of the accumulatorcontains a “1” (i.e., a voltage corresponding to a “1” on node S2 and avoltage corresponding to a “0” on node S1), transistor 209-1 does notconduct, the sense amplifier is not coupled to ground (as describedabove), and the data value previously stored in the sense amplifier 206remains unchanged (e.g., Row Y data value so the AND operation result isa “1” if the Row Y data value is a “1” and the AND operation result is a“0” if the Row Y data value is a “0”). This operation leaves the datavalue in the accumulator unchanged (e.g., from Row X).

After the result of the AND operation is initially stored in the senseamplifier 206, “Deactivate AND” in the pseudo code above indicates thatthe AND control signal goes low as shown at t₁₂ in FIG. 3, causing passtransistor 207-1 to stop conducting to isolate the sense amplifier 206(and data line 205-1 (D)) from ground. If not previously done, Row Y canbe closed (as shown at t₁₃ in FIG. 3) and the sense amplifier can bedisabled (as shown at t₁₄ in FIG. 3 by the ACT positive control signalgoing low and the RnIF negative control signal goes high). With the datalines isolated, “Precharge” in the pseudo code above can cause aprecharge of the data lines by an equilibrate operation, as describedpreviously (e.g., commencing at t₁₄ shown in FIG. 3).

FIG. 3 shows, in the alternative, the behavior of voltage signals on thedata lines (e.g., 205-1 (D) and 205-2 (D_) shown in FIG. 2) coupled tothe sense amplifier (e.g., 206 shown in FIG. 2) and the behavior ofvoltage signals on nodes S1 and S1 of the dynamic latch of the computecomponent (e.g., 231-1 shown in FIG. 2) for an AND logical operationinvolving each of the possible combination of operands (e.g., Row X/RowY data values 00, 10, 01, and 11).

Although the timing diagrams illustrated in FIG. 3 and the pseudo codedescribed above indicate initiating the AND logical operation afterstarting to load the second operand (e.g., Row Y data value) into thesense amplifier, the circuit shown in FIG. 2 can be successfullyoperated by initiating the AND logical operation before starting to loadthe second operand (e.g., Row Y data value) into the sense amplifier,the details of which are described below and illustrated with respect toFIGS. 9, 10, and 11.

FIG. 4 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure. FIG. 4 illustrates atiming diagram associated with initiating an OR logical operation afterstarting to load the second operand (e.g., Row Y data value) into thesense amplifier. FIG. 4 illustrates the sense amplifier and accumulatorsignals for various combinations of first and second operand datavalues. The particular timing diagram signals are discussed below withrespect to the pseudo code associated with an AND logical operation ofthe circuit shown in FIG. 2.

A subsequent operation phase can alternately be associated withperforming the OR operation on the first data value (now stored in thesense amplifier 206 and the dynamic latch of the accumulator 231-1) andthe second data value (stored in a memory cell 202-1 coupled to Row Y204-Y). The operations to load the Row X data into the sense amplifierand accumulator that were previously described with respect to timest₁-t₇ shown in FIG. 3 are not repeated with respect to FIG. 4. Examplepseudo code associated with “ORing” the data values can include:

Deactivate EQ

Open Row Y

Fire Sense Amps (after which Row Y data resides in the sense amps)

Close Row Y

-   -   When Row Y is closed, the sense amplifier still contains the Row        Y data value.

Activate OR

-   -   This results in the sense amplifier being written to the value        of the function (e.g., Row X OR Row Y), which may overwrite the        data value from Row Y previously stored in the sense amplifier        as follows:    -   If the accumulator contains a “0” (i.e., a voltage corresponding        to a “0” on node S2 and a voltage corresponding to a “1” on node        S1), the sense amplifier data remains unchanged (Row Y data)    -   If the accumulator contains a “1” (i.e., a voltage corresponding        to a “1” on node S2 and a voltage corresponding to a “0” on node        S1), the sense amplifier data is written to a “1”    -   This operation leaves the data in the accumulator unchanged.

Deactivate OR

Precharge

The “Deactivate EQ” (shown at t₈ in FIG. 4), “Open Row Y” (shown at t₉in FIG. 4), “Fire Sense Amps” (shown at t₁₀ in FIG. 4), and “Close RowY” (shown at t₁₃ in FIG. 4, and which may occur prior to initiating theparticular logical function control signal), shown in the pseudo codeabove indicate the same functionality as previously described withrespect to the AND operation pseudo code. Once the configuration ofselected Row Y is appropriately configured (e.g., opened if logicaloperation result is to be stored in memory cell corresponding to Row Yor closed to isolate memory cell if result if logical operation resultis not to be stored in memory cell corresponding to Row Y), “ActivateOR” in the pseudo code above indicates that the OR control signal goeshigh as shown at t₁₁ in FIG. 4, which causes pass transistor 207-2 toconduct. In this manner, activating the OR control signal causes thevalue of the function (e.g., Row X OR Row Y) to be written to the senseamp.

With the first data value (e.g., Row X) stored in the dynamic latch ofthe accumulator 231-1 and the second data value (e.g., Row Y) stored inthe sense amplifier 206, if the dynamic latch of the accumulatorcontains a “0” (i.e., a voltage corresponding to a “0” on node S2 and avoltage corresponding to a “1” on node S1), then the result of the ORoperation depends on the data value stored in the sense amplifier 206(e.g., from Row Y). The result of the OR operation should be a “1” ifthe data value stored in the sense amplifier 206 (e.g., from Row Y) is a“1,” but the result of the OR operation should be a “0” if the datavalue stored in the sense amplifier 206 (e.g., from Row Y) is also a“0.” The sensing circuitry 231-1 is configured such that if the dynamiclatch of the accumulator contains a “0,” with the voltage correspondingto a “0” on node S2, transistor 209-2 is off and does not conduct (andpass transistor 207-1 is also off since the AND control signal is notasserted) so the sense amplifier 206 is not coupled to ground (eitherside), and the data value previously stored in the sense amplifier 206remains unchanged (e.g., Row Y data value such that the OR operationresult is a “1” if the Row Y data value is a “1” and the OR operationresult is a “0” if the Row Y data value is a “0”).

If the dynamic latch of the accumulator contains a “1” (i.e., a voltagecorresponding to a “1” on node S2 and a voltage corresponding to a “0”on node S1), transistor 209-2 does conduct (as does pass transistor207-2 since the OR control signal is asserted), and the sense amplifier206 input coupled to data line 205-2 (D_) is coupled to ground since thevoltage corresponding to a “1” on node S2 causes transistor 209-2 toconduct along with pass transistor 207-2 (which also conducts since theOR control signal is asserted). In this manner, a “1” is initiallystored in the sense amplifier 206 as a result of the OR operation whenthe dynamic latch of the accumulator contains a “1” regardless of thedata value previously stored in the sense amp. This operation leaves thedata in the accumulator unchanged. FIG. 4 shows, in the alternative, thebehavior of voltage signals on the data lines (e.g., 205-1 (D) and 205-2(D_) shown in FIG. 2) coupled to the sense amplifier (e.g., 206 shown inFIG. 2) and the behavior of voltage signals on nodes S1 and S2 of thedynamic latch of the compute component (e.g., 231-1 shown in FIG. 2) foran OR logical operation involving each of the possible combination ofoperands (e.g., Row X/Row Y data values 00, 10, 01, and 11).

After the result of the OR operation is initially stored in the senseamplifier 206, “Deactivate OR” in the pseudo code above indicates thatthe OR control signal goes low as shown at t₁₂ in FIG. 4, causing passtransistor 207-2 to stop conducting to isolate the sense amplifier 206(and data line D 205-2) from ground. If not previously done, Row Y canbe closed (as shown at t₁₃ in FIG. 4) and the sense amplifier can bedisabled (as shown at t₁₄ in FIG. 4 by the ACT positive control signalgoing low and the RnIF negative control signal going high). With thedata lines isolated, “Precharge” in the pseudo code above can cause aprecharge of the data lines by an equilibrate operation, as describedpreviously and shown at t₁₄ in FIG. 4.

The sensing circuitry illustrated in FIG. 2 can provide additionallogical operations flexibility as follows. By substituting operation ofthe ANDinv control signal for operation of the AND control signal,and/or substituting operation of the ORinv control signal for operationof the OR control signal in the AND and OR operations described above,the logical operations can be changed from {Row X AND Row Y} to {˜Row XAND Row Y} (where “˜Row X” indicates an opposite of the Row X datavalue, e.g., NOT Row X) and can be changed from {Row X OR Row Y} to{˜Row X OR Row Y}. For example, during an AND operation involving theinverted data values, the ANDinv control signal can be asserted insteadof the AND control signal, and during an OR operation involving theinverted data values, the ORinv control signal can be asserted insteadof the OR control signal. Activating the ORinv control signal causestransistor 214-1 to conduct and activating the ANDinv control signalcauses transistor 214-2 to conduct. In each case, asserting theappropriate inverted control signal can flip the sense amplifier andcause the result initially stored in the sense amplifier 206 to be thatof the AND operation using inverted Row X and true Row Y data values orthat of the OR operation using the inverted Row X and true Row Y datavalues. A true or compliment version of one data value can be used inthe accumulator to perform the logical operation (e.g., AND, OR), forexample, by loading a data value to be inverted first and a data valuethat is not to be inverted second.

In a similar approach to that described above with respect to invertingthe data values for the AND and OR operations described above, thesensing circuitry shown in FIG. 2 can perform a NOT (e.g., invert)operation by putting the non-inverted data value into the dynamic latchof the accumulator and using that data to invert the data value in thesense amplifier 206. As previously mentioned, activating the ORinvcontrol signal causes transistor 214-1 to conduct and activating theANDinv control signal causes transistor 214-2 to conduct. The ORinvand/or ANDinv control signals are used in implementing the NOT function,as described further below:

Copy Row X into the Accumulator

-   -   Deactivate EQ    -   Open Row X    -   Fire Sense Amps (after which Row X data resides in the sense        amps)    -   Activate LOAD (sense amplifier data (Row X) is transferred to        nodes S1 and S2 of the Accumulator and resides there dynamically    -   Deactivate LOAD    -   Activate ANDinv and ORinv (which puts the compliment data value        on the data lines)        -   This results in the data value in the sense amplifier being            inverted (e.g., the sense amplifier latch is flipped)        -   This operation leaves the data in the accumulator unchanged    -   Deactivate ANDinv and ORinv    -   Close Row X    -   Precharge

The “Deactivate EQ,” “Open Row X,” “Fire Sense Amps,” “Activate LOAD,”and “Deactivate LOAD” shown in the pseudo code above indicate the samefunctionality as the same operations in the pseudo code for the “CopyRow X into the Accumulator” initial operation phase described aboveprior to pseudo code for the AND operation and OR operation. However,rather than closing the Row X and Precharging after the Row X data isloaded into the sense amplifier 206 and copied into the dynamic latch, acompliment version of the data value in the dynamic latch of theaccumulator can be placed on the data line and thus transferred to thesense amplifier 206 by enabling and disabling the invert transistors(e.g., ANDinv and/or ORinv). This results in the sense amplifier 206being flipped from the true data value that was previously stored in thesense amplifier to a compliment data value (e.g., inverted data value)stored in the sense amp. That is, a true or compliment version of thedata value in the accumulator can be transferred to the sense amplifierby activating and deactivating ANDinv and/or ORinv. This operationleaves the data in the accumulator unchanged.

Because the sensing circuitry 250 shown in FIG. 2 initially stores theresult of the AND, OR, and NOT logical operations in the sense amplifier206 (e.g., on the sense amplifier nodes), these logical operationresults can be communicated easily and quickly to any open row, any rowopened after the logical operation is complete, and/or into the dynamiclatch of the accumulator 231-1. The sense amplifier 206 and sequencingfor the AND, OR, and/or NOT logical operations can also be interchangedby appropriate activation of the AND, OR, ANDinv, and/or ORinv controlsignals (and operation of corresponding transistors having a gatecoupled to the particular control signal) before the sense amplifier 206fires.

When performing logical operations in this manner, the sense amplifier206 can be pre-seeded with a data value from the dynamic latch of theaccumulator to reduce overall current utilized because the sense amps206 are not at full rail voltages (e.g., supply voltage orground/reference voltage) when accumulator function is copied to thesense amplifier 206. An operation sequence with a pre-seeded senseamplifier 206 either forces one of the data lines to the referencevoltage (leaving the complementary data line at V_(DD)/2, or leaves thecomplementary data lines unchanged. The sense amplifier 206 pulls therespective data lines to full rails when the sense amplifier 206 fires.Using this sequence of operations will overwrite data in an open Row.

A SHIFT operation can be accomplished by multiplexing (“muxing”) twoneighboring data line complementary pairs using a traditional DRAMisolation (ISO) scheme. According to embodiments of the presentdisclosure, the shift circuitry 223 can be used for shifting data valuesstored in memory cells coupled to a particular pair of complementarydata lines to the sensing circuitry 250 (e.g., sense amplifier 206)corresponding to a different pair of complementary data lines (e.g.,such as a sense amplifier 206 corresponding to a left or right adjacentpair of complementary data lines. As used herein, a sense amplifier 206corresponds to the pair of complementary data lines to which the senseamplifier is coupled when isolation transistors 221-1 and 221-2 areconducting. The SHIFT operations (right or left) do not pre-copy the RowX data value into the accumulator. Operations to shift right Row X canbe summarized as follows:

Deactivate Norm and Activate Shift

Deactivate EQ

Open Row X

Fire Sense Amps (after which shifted Row X data resides in the senseamps)

Activate Norm and Deactivate Shift

Close Row X

Precharge

In the pseudo code above, “Deactivate Norm and Activate Shift” indicatesthat a NORM control signal goes low causing isolation transistors 221-1and 221-2 of the shift circuitry 223 to not conduct (e.g., isolate thesense amplifier from the corresponding pair of complementary datalines). The SHIFT control signal goes high causing isolation transistors221-3 and 221-4 to conduct, thereby coupling the sense amplifier 206 tothe left adjacent pair of complementary data lines (e.g., on the memoryarray side of non-conducting isolation transistors 221-1 and 221-2 forthe left adjacent pair of complementary data lines).

After the shift circuitry 223 is configured, the “Deactivate EQ,” “OpenRow X,” and “Fire Sense Amps” shown in the pseudo code above indicatethe same functionality as the same operations in the pseudo code for the“Copy Row X into the Accumulator” initial operation phase describedabove prior to pseudo code for the AND operation and OR operation. Afterthese operations, the Row X data value for the memory cell coupled tothe left adjacent pair of complementary data lines is shifted right andstored in the sense amplifier 206.

In the pseudo code above, “Activate Norm and Deactivate Shift” indicatesthat a NORM control signal goes high causing isolation transistors 221-1and 221-2 of the shift circuitry 223 to conduct (e.g., coupling thesense amplifier to the corresponding pair of complementary data lines),and the SHIFT control signal goes low causing isolation transistors221-3 and 221-4 to not conduct and isolating the sense amplifier 206from the left adjacent pair of complementary data lines (e.g., on thememory array side of non-conducting isolation transistors 221-1 and221-2 for the left adjacent pair of complementary data lines). Since RowX is still open, the Row X data value that has been shifted right istransferred to Row X of the corresponding pair of complementary datalines through isolation transistors 221-1 and 221-2.

After the Row X data values are shifted right to the corresponding pairof complementary data lines, the selected row (e.g., ROW X) is disabledas indicated by “Close Row X” in the pseudo code above, which can beaccomplished by the access transistor turning off to decouple theselected cell from the corresponding data line. Once the selected row isclosed and the memory cell is isolated from the data lines, the datalines can be precharged as indicated by the “Precharge” in the pseudocode above. A precharge of the data lines can be accomplished by anequilibrate operation, as described above.

Operations to shift left Row X can be summarized as follows:

Activate Norm and Deactivate Shift

Deactivate EQ

Open Row X

Fire Sense Amps (after which Row X data resides in the sense amps)

Deactivate Norm and Activate Shift

-   -   Sense amplifier data (shifted left Row X) is transferred to Row        X

Close Row X

Precharge

In the pseudo code above, “Activate Norm and Deactivate Shift” indicatesthat a NORM control signal goes high causing isolation transistors 221-1and 221-2 of the shift circuitry 223 to conduct, and the SHIFT controlsignal goes low causing isolation transistors 221-3 and 221-4 to notconduct. This configuration couples the sense amplifier 206 to acorresponding pair of complementary data lines and isolates the senseamplifier from the right adjacent pair of complementary data lines.

After the shift circuitry is configured, the “Deactivate EQ,” “Open RowX,” and “Fire Sense Amps” shown in the pseudo code above indicate thesame functionality as the same operations in the pseudo code for the“Copy Row X into the Accumulator” initial operation phase describedabove prior to pseudo code for the AND operation and OR operation. Afterthese operations, the Row X data value for the memory cell coupled tothe pair of complementary data lines corresponding to the sensecircuitry 250 is stored in the sense amplifier 206.

In the pseudo code above, “Deactivate Norm and Activate Shift” indicatesthat a NORM control signal goes low causing isolation transistors 221-1and 221-2 of the shift circuitry 223 to not conduct (e.g., isolate thesense amplifier from the corresponding pair of complementary datalines), and the SHIFT control signal goes high causing isolationtransistors 221-3 and 221-4 to conduct coupling the sense amplifier tothe left adjacent pair of complementary data lines (e.g., on the memoryarray side of non-conducting isolation transistors 221-1 and 221-2 forthe left adjacent pair of complementary data lines. Since Row X is stillopen, the Row X data value that has been shifted left is transferred toRow X of the left adjacent pair of complementary data lines.

After the Row X data values are shifted left to the left adjacent pairof complementary data lines, the selected row (e.g., ROW X) is disabledas indicated by “Close Row X,” which can be accomplished by the accesstransistor turning off to decouple the selected cell from thecorresponding data line. Once the selected row is closed and the memorycell is isolated from the data lines, the data lines can be prechargedas indicated by the “Precharge” in the pseudo code above. A precharge ofthe data lines can be accomplished by an equilibrate operation, asdescribed above.

According to various embodiments, general computing can be enabled in amemory array core of a processor-in-memory (PIM) device such as a DRAMone transistor per memory cell (e.g., 1T1C) configuration at6F{circumflex over ( )}2 or 4F{circumflex over ( )}2 memory cell sizes,for example. The advantage of the apparatuses and methods describedherein is not realized in terms of single instruction speed, but ratherthe cumulative speed that can be achieved by an entire bank of databeing computed in parallel without ever transferring data out of thememory array (e.g., DRAM) or firing a column decode. In other words,data transfer time can be eliminated. For example, apparatus of thepresent disclosure can perform ANDS or ORs simultaneously using datavalues in memory cells coupled to a data line (e.g., a column of 16 Kmemory cells).

In previous approach sensing circuits where data is moved out forlogical operation processing (e.g., using 32 or 64 bit registers), feweroperations can be performed in parallel compared to the apparatus of thepresent disclosure. In this manner, significantly higher throughput iseffectively provided in contrast to conventional configurationsinvolving a central processing unit (CPU) discrete from the memory suchthat data must be transferred therebetween. An apparatus and/or methodsaccording to the present disclosure can also use less energy/area thanconfigurations where the CPU is discrete from the memory. Furthermore,an apparatus and/or methods of the present disclosure can improve uponthe smaller energy/area advantages since the in-memory-array logicaloperations save energy by eliminating certain data value transfers.

FIG. 5 is a schematic diagram illustrating a portion of sensingcircuitry in accordance with a number of embodiments of the presentdisclosure. The sensing circuitry shown in FIG. 5 comprises a senseamplifier 506 and a compute component 533. The compute component 533 canhave various architectures such as those described above in associationwith FIG. 2 and as those described below in association with FIGS. 6-9,12, 13, and 18. In a number of embodiments, the compute componentcomprises an accumulator having an associated dynamic latch, forinstance. In a number of embodiments, a sense amplifier (e.g., 506) cancomprise a number of transistors formed on pitch with the transistors ofthe corresponding compute component (e.g., 533) and/or the memory cellsof an array (e.g., array 230 shown in FIG. 2) to which they are coupled,which may conform to a particular feature size (e.g., 4F², 6F², etc.).

As described further below, the sense amplifier 506 can, in conjunctionwith the compute component 533, be operated to perform various logicaloperations using data from an array as input. In a number ofembodiments, the result of a logical operation can be stored back to thearray without transferring the data via a data line address access(e.g., without firing a column decode signal such that data istransferred to circuitry external from the array and sensing circuitryvia local I/O lines). As such, a number of embodiments of the presentdisclosure can enable performing logical operations and computefunctions associated therewith using less power than various previousapproaches. Additionally, since a number of embodiments eliminate theneed to transfer data across I/O lines in order to perform computefunctions (e.g., between memory and discrete processor), a number ofembodiments can enable an increased parallel processing capability ascompared to previous approaches.

In the example illustrated in FIG. 5, the circuitry corresponding tosense amplifier 506 comprises a latch 515 including four transistorscoupled to a pair of complementary data lines D 505-1 and D_ 505-2.However, embodiments are not limited to this example. The latch 515 canbe a cross coupled latch (e.g., gates of a pair of transistors, such asn-channel transistors (e.g., NMOS transistors) 527-1 and 527-2 are crosscoupled with the gates of another pair of transistors, such as p-channeltransistors (e.g., PMOS transistors) 529-1 and 529-2). As describedfurther herein, the cross coupled latch 415 comprising transistors527-1, 527-2, 529-1, and 529-2 can be referred to as a primary latch.

The voltages or currents on the respective data lines D and D_ can beprovided to the respective latch inputs 533-1 and 533-2 of the crosscoupled latch 515 (e.g., the input of the secondary latch). In thisexample, the latch input 533-1 is coupled to a first source/drain regionof transistors 527-1 and 529-1 as well as to the gates of transistors527-2 and 529-2. Similarly, the latch input 533-2 can be coupled to afirst source/drain region of transistors 527-2 and 529-2 as well as tothe gates of transistors 527-1 and 529-1. The compute component 533(e.g., accumulator) can be coupled to latch inputs 533-1 and 533-2 ofthe cross coupled latch 515 as shown; however, embodiments are notlimited to the example shown in FIG. 5.

In this example, a second source/drain region of transistor 527-1 and527-2 is commonly coupled to a negative control signal 528 (RnIF). Asecond source/drain region of transistors 529-1 and 529-2 is commonlycoupled to a positive control signal 590 (ACT). The ACT signal 590 canbe a supply voltage (e.g., V_(DD)) and the RnIF signal can be areference voltage (e.g., ground). Activating signals 528 and 590 enablesthe cross coupled latch 515.

The enabled cross coupled latch 515 operates to amplify a differentialvoltage between latch input 533-1 (e.g., first common node) and latchinput 533-2 (e.g., second common node) such that latch input 533-1 isdriven to one of the ACT signal voltage and the RnIF signal voltage(e.g., to one of V_(DD) and ground), and latch input 533-2 is driven tothe other of the ACT signal voltage and the RnIF signal voltage.

The sense amplifier 506 can also include circuitry configured toequilibrate the data lines D and D_ (e.g., in association with preparingthe sense amplifier for a sensing operation). In this example, theequilibration circuitry comprises a transistor 524 having a firstsource/drain region coupled to a first source/drain region of transistor525-1 and data line D 505-1. A second source/drain region of transistor524 can be coupled to a first source/drain region of transistor 525-2and data line D_ 505-2. A gate of transistor 524 can be coupled to gatesof transistors 525-1 and 525-2.

The second source drain regions of transistors 525-1 and 525-2 arecoupled to an equilibration voltage 538 (e.g., V_(DD)/2), which can beequal to V_(DD)/2, where V_(DD) is a supply voltage associated with thearray. The gates of transistors 524, 525-1, and 525-2 can be coupled tocontrol signal 525 (EQ). As such, activating EQ enables the transistors524, 525-1, and 525-2, which effectively shorts data line D to data lineD_ such that the data lines D and D_ are equilibrated to equilibrationvoltage V_(DD)/2. According to various embodiments of the presentdisclosure, a number of logical operations can be performed using thesense amplifier, and storing the result in the compute component (e.g.,accumulator).

FIG. 6 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Thecircuit illustrated in FIG. 6 is similar to the circuit illustrated inFIG. 2 but with an alternative compute component 631-2 configurationhaving a modified invert implementation, as shown in FIG. 6 (anddescribed below). The circuit illustrated in FIG. 6 can have a senseamplifier 606 coupled between data lines D 605-1 and D_ 605-2, and canhave shift circuitry 623 coupled intermediate within and betweendifferent pairs of data lines D 605-1 and D_ 605-2, for example.

In the example illustrated in FIG. 6, the circuitry corresponding tocompute component 631-2 implements a latch (e.g., a secondary latch)that includes eight transistors. The compute component 631-2 can operateas/be, for example, an accumulator. The compute component 631-2 can becoupled to each of the data lines D 605-1 and D 605-2 as shown in FIG.6. However, embodiments are not limited to this example. The transistorsof compute component 631-2 can all be n-channel transistors (e.g., NMOStransistors), for example.

The voltages or currents on the respective data lines D 605-1 and D_605-2 can be communicated to the respective inputs of the computecomponent 631-2 (e.g., inputs of the secondary latch). In this example,data line D 605-1 can be coupled to a first source/drain region of afirst pass transistor 607-1 as well as to a first source/drain region ofload transistor 618-2 and invert transistor 636-1. Data line D_ 605-2can be coupled to a first source/drain region of pass transistor 607-2as well as to a first source/drain region of load transistor 618-1 andinvert transistor 636-2.

The gates of load transistor 618-1 and 618-2 can be commonly coupled toa LOAD control signal. A second source/drain region of load transistor618-1 can be directly coupled to a gate of transistor 609-1, the gate oftransistor 609-1 being referred to as node S1. A second source/drainregion of load transistor 618-2 can be directly coupled to a gate oftransistor 609-2, the gate of transistor 609-2 being referred to as nodeS2.

A second source/drain region of inverting transistor 636-1 can bedirectly coupled to a gate of transistor 609-1 and a second source/drainregion of load transistor 618-1. A second source/drain region ofinverting transistor 636-2 can be directly coupled to a gate oftransistor 609-2 and a second source/drain region of load transistor618-2. A second source/drain region of transistors 609-1 and 609-2 canbe commonly coupled to a negative reference signal control line 691-1providing a reference signal (e.g., ground (GND)). A gate of passtransistor 607-1 can be coupled to a control signal AND. A gate of passtransistor 607-2 can be coupled to a control signal OR. A gate of inverttransistor 636-1 can be coupled to a control signal LOADinv. A gate ofinvert transistor 636-2 can also be coupled to the control signalLOADinv.

The circuit shown in FIG. 6 stores accumulator data dynamically on nodesS1 and S2. Activating the LOAD control signal causes load transistors618-1 and 618-2 to conduct, and thereby load complementary data ontonodes S1 and S2. Note however that the data value corresponding to dataline D_ 605-2 is loaded onto node S1 and the data value corresponding todata line D 605-1 is loaded onto node S2. The LOAD control signal can beelevated to a voltage greater than V_(DD) to pass a full V_(DD) level toS1/S2. However, elevating the LOAD control signal to a voltage greaterthan V_(DD) is optional, and functionality of the circuit shown in FIG.6 is not contingent on the LOAD control signal being elevated to avoltage greater than V_(DD).

The circuit illustrated in FIG. 6 is a modification of the circuitillustrated in FIG. 2 with respect to the configuration of theaccumulator transistors. According to various embodiments of the presentdisclosure, the circuit of FIG. 6 can be operated to load a true orcompliment data value into the accumulator, rather than loading a truedata value into the accumulator and subsequently selecting to use thetrue or compliment data value while performing operations to implementlogical operations, as described with respect to the circuit illustratedin FIG. 2. The NOT (e.g., invert) function can be accomplished using thecircuit illustrated in FIG. 6 by first loading the inverse data valueinto the accumulator directly, which can be subsequently used withoutfurther operations to invert it.

FIG. 7 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Thecircuit illustrated in FIG. 7 is similar to the circuit illustrated inFIG. 6 but with an alternative compute component 731-3 configurationhaving a modified invert implementation, as explicitly shown in FIG. 7(and described below).

As shown in FIG. 7, within compute component 731-3 load transistors718-1 and 718-2 can correspond to load transistors 618-1 and 618-2 shownin FIG. 6, transistor 707-1 (with gate coupled to the AND controlsignal) can correspond to transistor 607-1 shown in FIG. 6, transistor707-2 (with gate coupled to the OR control signal) can correspond totransistor 607-1 shown in FIG. 6, transistor 709-1 (with gate being nodeS1) can correspond to transistor 609-1 shown in FIG. 6, and transistor709-2 (with gate being node S2) can correspond to transistor 609-1 shownin FIG. 6.

The compute component 731-3 shown in FIG. 7 is different from thecompute component 631-3 shown in FIG. 6 by not including inverttransistors (e.g., 636-1 and 636-2 shown in FIG. 6). Therefore, theconnections of other circuit elements to the invert transistors asdescribed with respect to FIG. 6 do not exist with respect to thecompute component 731-3 shown in FIG. 7. Eliminating the two inverttransistors from the circuit shown in FIG. 7 compared to the circuitshown in FIG. 6 (e.g., eliminating invert transistors 636-1 and 636-2shown in FIG. 6) can result in an approximately four percent (4%)smaller die size.

In addition, the second source/drain region of transistors 709-1 and709-2 are commonly coupled to a different reference signal indicated onFIG. 7 as “INVGND,” which represents an elevated reference voltage(e.g., approximately 3.0 V) having a potential elevated to a voltagegreater than a ground reference voltage (e.g., GND shown in FIG. 6).While a specific example voltage is provided above, embodiments of thepresent disclosure are not limited to the particular magnitude provided,and the elevated reference voltage can be higher, or lower, than 3.0 V,as long as the magnitude of the elevated reference voltage is greaterthan ground (e.g., about 0.0 V). According to some embodiments, theelevated reference voltage can be configured with the capability toswitch between a low reference voltage (e.g., ground) and an elevatedreference voltage.

To accomplish a NOT logic function (e.g., invert) using the differentconfiguration of compute component 731-3 (with respect to theconfiguration of compute component 631-2) and the elevated referencevoltage, the sense amplifier 706 coupled between data lines 705-1 (D)and 705-2 (D_) is precharged (e.g., “readied”) for a sense operation.The INVGND signal 791-2 is then switched from a low reference voltage(e.g., ground) to an elevated reference voltage, which produces avoltage separation on the complementary data lines that can be loadedinto and distinguished by the sense amp.

FIG. 8 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Thecircuit illustrated in FIG. 8 is similar to the circuit illustrated inFIG. 7 but with an alternative compute component 831-4 configurationhaving a modified invert implementation, as explicitly shown in FIG. 8(and described below).

As shown in FIG. 8, within compute component 831-4 load transistors818-1 and 818-2 can correspond to load transistors 718-1 and 718-2 shownin FIG. 7, transistor 807-1 (with gate coupled to the AND controlsignal) can correspond to transistor 707-1 shown in FIG. 7, transistor807-2 (with gate coupled to the OR control signal) can correspond totransistor 707-1 shown in FIG. 7, transistor 809-1 (with gate being nodeS1) can correspond to transistor 709-1 shown in FIG. 7, and transistor809-2 (with gate being node S2) can correspond to transistor 709-1 shownin FIG. 7. Also like the compute component 731-3 shown in FIG. 7, thecompute component 831-4 does not include invert transistors (e.g., 636-1and 636-2 shown in FIG. 6).

Unlike the compute component 731-3 shown in FIG. 7, the negativereference signal control line 891-1 in the compute component 831-4 doesnot provide an elevated reference voltage and is not configured toswitch from a low reference voltage to an elevated reference voltage.Rather, the negative reference signal control line 891-1 in the computecomponent 831-4 provides a reference signal (e.g., ground (GND)) as wasdescribed with respect to negative reference signal control line 691-1shown in FIG. 6.

The shift circuitry 823-1 shown in the circuit illustrated in FIG. 8 isconfigured differently than the shift circuitry 723 shown in the circuitillustrated in FIG. 7 (shift circuitry configuration is described withrespect to FIG. 2). The isolation transistors 821-1 and 821-2 havingrespective gates commonly coupled to the NORM control signal, andisolation transistors 821-3 and 821-4 having respective gates commonlycoupled to the SHIFT control signal 819 are arranged in shift circuitry823-1 in the same manner described for isolation transistors 221-1,221-2, 221-3, and 221-4 shown in FIG. 2. The NORM and SHIFT controlsignals operate as described with respect to FIG. 2.

However, shift circuitry 823-1 shown in FIG. 8 includes an additional apair of invert transistors (e.g., 837-1 and 837-2) in addition to theisolation transistors 221-1, 221-2, 221-3, and 221-4 shown in, anddescribed with respect to, FIG. 2. A first source/drain region of inverttransistor 837-1 is directly coupled to data line D_ 805-2 and a secondsource/drain region of invert transistor 837-1 is directly coupled todata line D 805-1. A first source/drain region of invert transistor837-2 is directly coupled to data line D 805-1 and a second source/drainregion of invert transistor 837-2 is directly coupled to data line D805-2. Respective gates of invert transistors 837-1 and 837-2 arecommonly coupled to an invert (INV) control signal.

The NOT logical operation (invert) can be accomplished by multiplexing(“muxing”) data lines through the shift circuitry 823-1 (e.g., at theisolation gate level). The invert transistors 837-1 and 837-2 arearranged to communicate the data value corresponding to the voltage fromone of the complementary data lines on a memory array side of the shiftcircuitry 823-1 to the other one of the complementary data lines on asensing circuitry side of the shift circuitry 823-1 when the INV controlsignal is activated. That is, when the INV control signal is activatedand the invert transistors 837-1 and 837-2 are conducting, data line D_805-2 is coupled to data line D 805-1 through invert transistor 837-1,and data line D 805-1 is coupled to data line D_ 805-2 through inverttransistor 837-2. In this manner, an inverted data value can be loadedinto the sense amplifier 806 and/or the accumulator 831-4.

The isolation transistors 821-1, 821-2, 821-3, and 821-4, together withthe invert transistors 837-1 and 837-2, can be operated as a 3-to-1multiplexor in the shift circuitry 823-1 to accomplish the SHIFT andinvert functions. That is, one of 3 data lines (e.g., adjacent rightdata lines, adjacent left data lines, or opposite data lines of acomplementary pair) can be coupled to the output of the shift circuitry823-1 that is coupled to data line D 805-1 and D_ 805-2.

FIG. 9 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Thecircuit illustrated in FIG. 9 is similar to the circuit illustrated inFIG. 2 but with an alternative compute component 931-5 configurationhaving a modified invert implementation, as explicitly shown in FIG. 9(and described below).

In the example illustrated in FIG. 9, the circuitry corresponding tocompute component 931-5 implements a dynamic latch, which can bereferred to herein as a secondary latch. The secondary latch of thecompute component 931-5 can serve as an accumulator. As such, thecompute component 931-5 can be referred to herein as an accumulator. Thecompute component 931-5 can be coupled to each of the data lines D 905-1and D_ 905-2 as shown in FIG. 9. However, embodiments are not limited tothis example. The transistors of compute component 931-5 can all ben-channel transistors (e.g., NMOS transistors), for example.

In this example, data line D 905-1 can be coupled to a firstsource/drain region of transistors 916-1 and 939-1, as well as to afirst source/drain region of load transistor 918-1. Data line D_ 905-2can be coupled to a first source/drain region of transistors 916-2 and939-2, as well as to a first source/drain region of load transistor918-2.

The gates of load transistor 918-1 and 918-2 can be commonly coupled toa LOAD control signal. A second source/drain region of load transistor918-1 can be directly coupled to the gates of transistors 916-1 and939-2. A second source/drain region of load transistor 918-2 can bedirectly coupled to the gates of transistors 916-2 and 939-1.

A second source/drain region of transistor 916-1 can be directly coupledto a first source/drain region of pull-down transistor 914-1. A secondsource/drain region of transistor 939-1 can be directly coupled to afirst source/drain region of pull-down transistor 907-1. A secondsource/drain region of transistor 916-2 can be directly coupled to afirst source/drain region of pull-down transistor 914-2. A secondsource/drain region of transistor 939-2 can be directly coupled to afirst source/drain region of pull-down transistor 907-2. A secondsource/drain region of each of pull-down transistors 907-1, 907-2,914-1, and 914-2 can be commonly directly coupled to a reference voltage991-1 (e.g., ground (GND)). A gate of pull-down transistor 907-1 can becoupled to an AND control signal line, a gate of pull-down transistor914-1 can be coupled to an ANDinv control signal line 913-1, a gate ofpull-down transistor 914-2 can be coupled to an ORinv control signalline 913-2, and a gate of pull-down transistor 907-2 can be coupled toan OR control signal line.

The gate of transistor 939-1 can be referred to as node S1, and the gateof transistor 939-2 can be referred to as node S2. The circuit shown inFIG. 9 stores accumulator data dynamically on nodes S1 and S2.Activating the LOAD control signal causes load transistors 918-1 and918-2 to conduct, and thereby load complementary data onto nodes S1 andS2. The LOAD control signal can be elevated to a voltage greater thanV_(DD) to pass a full V_(DD) level to S1/S2. However, elevating the LOADcontrol signal to a voltage greater than V_(DD) is optional, andfunctionality of the circuit shown in FIG. 9 is not contingent on theLOAD control signal being elevated to a voltage greater than V_(DD).

The configuration of compute component 931-5 shown in FIG. 9 includestwo (2) additional transistors than the configuration of computecomponent 231-1 shown in FIG. 2. However, the configuration of computecomponent 931-5 shown in FIG. 9 has the benefit of balancing the senseamplifier for functionality when the pull-down transistors 907-1, 907-2,914-1, and 914-2 are conducting before the sense amplifier 906 is fired(e.g., during pre-seeding of the sense amplifier 906). As used herein,firing the sense amplifier 906 refers to enabling the sense amplifier906 to set the primary latch and subsequently disabling the senseamplifier 906 to retain the set primary latch. Performing logicaloperations after equilibration is deactivated (in the sense amp), butbefore the sense amplifier fires, can save power usage because the latchof the sense amplifier does not have to be “flipped” using full railvoltages (e.g., V_(DD), GND).

Inverting transistors that pull-down a respective data line inperforming certain logical operations, including transistor 916-1(having a gate coupled to S2 of the dynamic latch) in series withtransistor 914-1 (having a gate coupled to an ANDinv control signal line913-1), and transistor 916-2 (having a gate coupled to S1 of the dynamiclatch) in series with transistor 914-2 (having a gate coupled to anORinv control signal line 913-2) can operate to pull one of the datalines 905-1 or 905-2 to a ground reference potential so as to invert afirst operand of a logical operation.

By substituting operation of the ANDinv control signal for operation ofthe AND control signal, and/or substituting operation of the ORinvcontrol signal for operation of the OR control signal in the AND and ORoperations described above, the logical operations can be changed from{Row X AND Row Y} to {˜Row X AND Row Y} (where “˜Row X” indicates anopposite of the Row X data value, e.g., NOT Row X) and can be changedfrom {Row X OR Row Y} to {˜Row X OR Row Y}. For example, during an ANDoperation involving the inverted data values, the ANDinv control signalcan be asserted instead of the AND control signal, and during an ORoperation involving the inverted data values, the ORInv control signalcan be asserted instead of the OR control signal. Activating the ORinvcontrol signal causes transistor 914-1 to conduct and activating theANDinv control signal causes transistor 914-2 to conduct.

In each case, asserting the appropriate inverted control signal can flipthe sense amplifier and cause the result initially stored in the senseamplifier 906 to be that of the AND operation using inverted Row X andtrue Row Y data values or that of the OR operation using the invertedRow X and true Row Y data values. A true or compliment version of onedata value can be used in the accumulator to perform the logicaloperation (e.g., AND, OR), for example, by loading a data value to beinverted first and a data value that is not to be inverted second.

FIG. 10 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure. FIG. 10 illustrates atiming diagram associated with initiating an AND logical operationbefore starting to load the second operand (e.g., Row Y data value) intothe sense amplifier. FIG. 10 illustrates the sense amplifier andaccumulator signals for various combinations of first and second operanddata values. FIG. 10 shows the respective sense amplifier andaccumulator signals corresponding to each combination of Row X datavalue and Row Y data value in each set. The particular timing diagramsignals are discussed below with respect to the pseudo code associatedwith an AND operation of the circuit shown in FIG. 9.

Operations to load data (e.g., Row X) into the accumulator 931-5 are thesame as described with respect to the accumulator 231-1 for the circuitshown and described with respect to FIG. 2 and the timing diagramillustrated in FIG. 3 (e.g., operations at times t₁ through t₇). Oncethe data value (e.g., Row X) is stored in the sense amplifier 906 andcopied to the dynamic latch of the accumulator, example operations toAND Row X with Row Y can be summarized as follows:

Deactivate EQ

Open Row Y

Activate AND

-   -   This results in the sense amplifier being written with AND        result data:        -   If the accumulator contains a “0” (i.e., a voltage            corresponding to a “0” on node S2 and a voltage            corresponding to a “1” on node S1), then the sense amplifier            data are forced to a “0”        -   If the accumulator contains a “1” (i.e., a voltage            corresponding to a “1” on node S2 and a voltage            corresponding to a “0” on node S1), then the sense amplifier            data remains unchanged and will sense what is contained in            Row Y    -   This operation leaves the data in the accumulator unchanged.

Fire Sense Amps

-   -   Result of AND function resides in the sense amp    -   Result of the AND function is also written to Row Y (Row Y is        open). Alternatively, Row Y can be first copied to the resultant        Row before this function is performed.

Close Row Y

Deactivate AND

Precharge

In the pseudo code above, “Deactivate EQ” shown at t₈ in FIG. 10 and“Open Row Y” shown at t₉ in FIG. 10 are the same as described above withrespect to FIG. 2 and the timing diagram illustrated in FIG. 3implementing an AND operation. The sense amps 906 are fired at t₁₀ afterRow Y is opened as shown in FIG. 10. However, different from the timingof operations shown in FIG. 3, and as shown in FIG. 10, the “ActivateAND” in the pseudo code above occurs before firing the sense amps withrespect to the sensing circuitry illustrated in FIG. 9. That is, t₁₁occurs before t₁₀, as illustrated in FIG. 10.

The “Activate AND” in the pseudo code above indicates that the ANDcontrol signal goes high as shown at t₁₁ in FIG. 10, causing pull-downtransistor 907-1 to conduct. Depending on the data value (e.g., from RowX) loaded into the accumulator 931-5, the sensing circuitry illustratedin FIG. 9 is configured to either sense the Row Y data value normally(e.g., when the data value (e.g., from Row X) loaded into theaccumulator 931-5 is a “1”) or force the sense amplifier 906 to store a“0” (e.g., when the data value (e.g., from Row X) loaded into theaccumulator 931-5 is a “0”), as described further below. According tovarious embodiments, the “Activate AND” in the pseudo code can alsooccur prior to, or simultaneous with, opening Row Y and result in thecorrect result being stored in the sense amps when subsequently fired.

Although the pseudo code above indicates that “Deactivate AND” occursafter the sense amps are fired, “Deactivate AND” can occur in proximityto (e.g., just before, at the same time, or just after) the sense ampsfiring since the “Activate AND” operation has already begun toappropriately modify the voltages present on the data lines D and D_from the equilibrate voltage (e.g., V_(DD)/2), which firing the senseamplifier drives the voltage on the data lines D and D_ to therespective rails. In this manner, activating the AND control signalcauses the value of the function (e.g., Row X AND Row Y) to be reflectedon the data lines D and D_ and written to the sense amplifier 906 whenit fires thereafter.

With the first data value (e.g., Row X) stored in the dynamic latch ofthe accumulator 931-5 and in the sense amplifier 906, and the seconddata value (e.g., Row Y) impacting the voltages present on the datalines 905-1 (D) and 905-2 (D_), if the dynamic latch of the accumulator931-5 contains a “0” (i.e., a voltage corresponding to a “0” on node S2(which is coupled to data line D through load transistor 918-1) and avoltage corresponding to a “1” on node S1), the sense amplifier data iswritten to a “0” (regardless of the Row Y data value initially indicatedthe on the data lines 905-1 (D) and 905-2 (D_)). The voltagecorresponding to a “1” on node S1 is applied to the gate of transistor939-1, which causes transistor 939-1 to conduct thereby coupling thesense amplifier 1306 to ground through transistor 939-1, pull-downtransistor 907-1 (conducting due to the AND control signal being high),and data line D 905-1. When either data value of an AND operation is“0,” the result is a “0.” When the first data value (e.g., from Row Xstored in the dynamic latch) is a “0,” the result of the AND operationis a “0” regardless of the state of the second data value (e.g., fromRow Y), and so the configuration of the sensing circuitry causes the “0”result to be written and initially stored in the sense amplifier 906.This operation leaves the data value in the accumulator unchanged (e.g.,from Row X).

If the dynamic latch of the accumulator contains a “1” (e.g., from RowX), then the result of the AND operation depends on the data valuestored in Row Y. The result of the AND operation should be a “1” if thedata value stored in Row Y is a “1,” but the result of the AND operationshould be a “0” if the data value stored in Row Y is a “0.” The sensingcircuitry 931-5 is configured such that if the dynamic latch of theaccumulator contains a “1” (i.e., a voltage corresponding to a “1” onnode S2 and a voltage corresponding to a “0” on node S1), the Row Y datavalue on the data lines 905-1 (D) and 905-2 (D_) is sensed normally.Transistor 939-1 does not conduct, and although transistor 907-1 isconducting due to the AND control signal applied to the gate oftransistor 907-1, the sense amplifier 906 is not coupled to groundthrough data line 905-1, and the data value previously stored in thesense amplifier 906 remains unchanged (e.g., Row X data value so the ANDoperation result is a “1” if the Row Y data value is a “1” and the ANDoperation result is a “0” if the Row Y data value is a “0”). The senseamplifier 906 is also not coupled to ground via data line 905-2 sincetransistor 907-2 is not conducting (even though transistor 939-2 isconducting due to a “1” on node S2). This AND operation leaves the datavalue in the accumulator unchanged (e.g., from Row X).

After the “Activate AND” signal causes pull-down transistor 907-1 toconduct and change the voltage on data line 905-1 from the equilibratevoltage, “Fire Sense Amps” in the pseudo code above indicates that thesense amplifier 906 is enabled to amplify the differential signalbetween D 905-1 and D_ 905-2, resulting in a voltage (e.g., V_(DD))corresponding to a logic 1 or a voltage (e.g., GND) corresponding to alogic 0 being on data line D 905-1 (and the voltage corresponding to theother logic state being on complementary data line D_ 905-2). Thedynamic latch still corresponds to the data value from memory cellcoupled to Row X since the dynamic latch is unchanged. However, sinceRow Y is open the result of the AND function is also written to Row Y.Alternatively, Row Y can be first copied to a resultant Row (and theResultant Row left open) before this function is performed.

FIG. 10 shows, in the alternative, the behavior of voltage signals onthe data lines (e.g., 905-1 (D) and 905-2 (D_) shown in FIG. 9) coupledto the sense amplifier (e.g., 906 shown in FIG. 9) and the behavior ofvoltage signals on nodes S1 and S2 of the dynamic latch of the computecomponent (e.g., 931-5 shown in FIG. 9) for an AND logical operationinvolving each of the possible combination of operands (e.g., Row X/RowY data values 00, 10, 01, and 11).

Although the pseudo code above indicates that Close Row Y” occurs before“Deactivate AND,” the timing diagram illustrated in FIG. 10 shows thatthe AND control signal goes low while Row Y remains open. Variousembodiments of the present disclosure can include the “Deactivate AND”occurring before, or after, Row Y closes. The result of the ANDoperation is fixed by operation of the primary latch once the senseamplifier fires.

After the sense amps fire and the result is also stored in Row Y (oranother resultant Row) of the memory array, in the pseudo code above,“Close Row Y” indicates that the selected row (e.g., Row Y) is disabled,which can be accomplished by the access transistor turning off todecouple the selected cell from the data line D 905-1. Once the selectedRow Y is closed and the memory cell is isolated.

Before (shown in timing diagram of FIG. 10) or after (indicated inpseudo code) Row Y is closed, “Deactivate AND” in the pseudo code aboveindicates that the AND control signal goes low, causing pull-downtransistor 907-1 to stop conducting and isolate the sense amplifier 906(and data line D 905-1) from ground (regardless of the data value storedin the dynamic latch, which may cause transistor 939-1 to beconducting). With the data lines isolated, “Precharge” in the pseudocode above can cause a precharge of the data lines by an equilibrateoperation, as described previously.

FIG. 11 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure. A subsequent operationphase can alternately be associated with performing the OR operation onthe first data value (e.g., Row X data value stored in the senseamplifier 906 and the dynamic latch of the accumulator 931-5) and thesecond data value (e.g., Row Y data value stored in a memory cell)).FIG. 11 illustrates a timing diagram associated with initiating an ORlogical operation before starting to load the second operand (e.g., RowY data value) into the sense amplifier. FIG. 11 illustrates the senseamplifier and accumulator signals for various combinations of first andsecond operand data values. The particular timing diagram signals arediscussed below with respect to the pseudo code associated with an ANDlogical operation of the circuit shown in FIG. 9.

Operations to load data (e.g., Row X) into the accumulator 931-5 are thesame as described above with respect to performing an AND logicaloperation. Once the data value (e.g., Row X) is stored in the senseamplifier 906 and copied to the dynamic latch of the accumulator,example operations to OR Row X with Row Y can be summarized as follows:

Deactivate EQ

Open Row Y

-   -   This modifies the voltage on the data lines from the equilibrate        voltage based on the Row Y data value.

Activate OR

-   -   This results in the sense amplifier being written to the value        of the function (e.g., Row X OR Row Y). This operation leaves        the data in the accumulator unchanged.

Fire Sense Amps

-   -   Drives the voltages on the data lines to the rails    -   Result of OR function resides in the sense amp    -   Result of the OR function is also written to Row Y (Row Y is        open—alternatively, Row Y can be first copied to the resultant        Row before this function is performed)

Deactivate OR

Close Row Y

Precharge

In the pseudo code above, “Deactivate EQ” shown at t₈ in FIG. 11 and isthe same as described above with respect the AND logical operationinvolving FIG. 9 and the timing diagram illustrated in FIG. 10. The“Activate OR” in the pseudo code above occurs before firing the senseamps with respect to the sensing circuitry illustrated in FIG. 9. Thatis, t₁₁ occurs before t₁₀, as illustrated in FIG. 11.

After equilibration is deactivated and with the Row X data value storedin the sense amplifier 906 and the dynamic latch of the accumulator931-5, a selected row for the second operand of the OR logical operation(e.g., ROW Y) is enabled as indicated in the pseudo code above by “OpenRow Y” and shown in FIG. 11 at t₉. When the voltage signal applied toROW Y reaches the threshold voltage (Vt) of the access transistorcorresponding to the selected cell coupled to Row Y, the accesstransistor turns on and couples the data line (e.g., D_ 905-1) to theselected cell which can attempt to create a differential voltage signalbetween the data lines.

The “Activate OR” in the pseudo code above indicates that the OR controlsignal goes high as shown at t₁₁ in FIG. 11, causing pull-downtransistor 907-2 to conduct. This operation leaves the data in senseamplifier and the accumulator unchanged. If the accumulator contains a“0” (Row X data) (i.e., a voltage corresponding to a “0” on node S2 anda voltage corresponding to a “1” on node S1), the pull-down transistoris conducting (by the OR control signal being high) but thecomplementary data line (D_) is not pulled-down because transistor 939-2is off and the sense amplifier data remains unchanged (Row X data) untilRow Y is opened. If the accumulator contains a “1” (Row X data) (i.e., avoltage corresponding to a “1” on node S2 and a voltage corresponding toa “0” on node S1), the complementary data line (D_) is pulled-downbecause the pull-down transistor is conducting (by the OR control signalbeing high) and transistor 939-2 is conducting (by the S2 voltage beinghigh) so the sense amplifier data remains unchanged (Row X data) for thetime being.

Although the pseudo code above shows that “Activate OR” occurs after RowY is opened, according to various embodiments “Activate OR” can occursimultaneous to or before opening Row Y. The sensing circuitry shown inFIG. 9 is configured to force the sense amplifier to a “1” if theaccumulator contains a “1” (Row X data) when the “Activate OR” occursand configured to sense the Row Y data value normally if the accumulatorcontains a “0” (Row X data) when the “Activate OR” occurs whether theRow Y memory cell is coupled to the data lines before, simultaneouslyto, or after the “Activate OR” occurs. In contrast to the operationsillustrated in FIG. 4, FIG. 11 shows the “Activate OR” occurring priorto firing the sense amps.

If the accumulator contains a “1” (i.e., a voltage corresponding to a“1” on node S2 and a voltage corresponding to a “0” on node S1), thecomplementary data line (D_) is pulled-down by the compute component931-5 (as described above) and the sense amplifier data of a “1” remainsunchanged regardless of the Row Y data (e.g., memory cell charge cannotovercome the pull-down). If the accumulator contains a “0” (i.e., avoltage corresponding to a “0” on node S2 and a voltage corresponding toa “1” on node S1), the complementary data line (D_) is not pulled-downby the compute component 931-5 (as described above), and if the Row Ydata is also a “0” the sense amplifier data remains unchanged by the RowY data. If the accumulator contains a “0” (i.e., a voltage correspondingto a “0” on node S2 and a voltage corresponding to a “1” on node S1),the complementary data line (D_) is not pulled-down by the computecomponent 931-5 (as described above), and if the Row Y data is also a“1” the sense amplifier data is written to a “1” based on the Row Ydata. Opening Row Y leaves the data in the accumulator unchanged.

“Fire Sense Amps” in the pseudo code above indicates that the senseamplifier 906 is enabled to amplify the differential signal between D905-1 and D 905-2, resulting in a voltage (e.g., V_(DD)) correspondingto a logic 1 or a voltage (e.g., GND) corresponding to a logic 0 beingon data line D 905-1 (and the voltage corresponding to the other logicstate being on complementary data line D_ 905-2). That is, firing thesense amps drives the voltages on the data lines to the rails. Firingthe sense amps results in the sense amplifier being written to the valueof the function (e.g., Row X OR Row Y), which may overwrite the datavalue from Row X previously stored in the sense amp. Since Row Y isopen, the result of the OR function is also written to Row Y.Alternatively, Row Y can be first copied to a resultant Row (and theResultant Row left open) before this function is performed. The dynamiclatch still corresponds to the data value from memory cell coupled toRow X since the dynamic latch is unchanged.

The “Deactivate OR” in the pseudo code above indicates that the ORcontrol signal goes low as shown at t₁₂ in FIG. 11, causing pull-downtransistor 907-2 to not conduct and terminating pull-down of thecomplementary data line (D_) if previously pulled-down.

“Close Row Y” in the pseudo code above indicates that the memory cellcoupled to Row Y is isolated from the data line (D), and with the datalines isolated, “Precharge” in the pseudo code above indicates aprecharge of the data lines by an equilibrate operation, as describedpreviously. As similarly discussed above with respect to the AND logicaloperation of the sense amplifier 906 and the compute component 931-5,Row Y can be opened before the logical operation control signal isactivated (e.g., OR control signal goes high), Row Y can be closedbefore the OR control signal is deactivated, the OR control signal canbe deactivated in proximity to the sense amplifier firing, and/or the ORcontrol signal can be deactivated after the sense amplifier firing iscomplete. Also, “Activate OR” can occur after the sense amplifierfiring, as described with respect to FIGS. 2 and 4.

FIG. 12 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Thecircuit illustrated in FIG. 12 is similar to the circuit illustrated inFIG. 9. Compute component 1231-5 can correspond to compute component931-5. However, the configuration shown in FIG. 12 (and described below)includes a shift circuitry 1257 that is different in location andinternal configuration from shift circuitry 923 shown in FIG. 9. Theshift circuitry 1257 illustrated in FIG. 12 does not include isolationtransistors in the complementary data lines to divide the complementarydata lines into two portions.

Shift circuitry 1257 can be located and/or connections from the shiftcircuitry 1257 to the respective complementary data lines between thesense amplifier and the accumulator (whereas the shift circuitry 923shown in FIG. 9 was located between the sense amplifier and the array ofmemory cells). The shift circuitry 1257 can be configured to selectivelycouple a plurality of data lines directly to the nodes of a dynamiclatch of compute component 1231-5. According to various embodiments,compute component 1231-5 can otherwise be configured the same as computecomponent 931-5 illustrated and described with respect to FIG. 9.

According to various embodiments of the present disclosure, the shiftcircuitry 1257 can include transistor(s) coupled between adjacent datalines and a node (e.g., S1, S2) of a dynamic latch coupled through loadtransistors to in the compute component 1231-5 to data lines associatedwith the compute component 1231-5. For example, shift circuitry 1257 caninclude a transistors coupled between a data line of a pair ofcomplementary data lines to one of the nodes of a dynamic latch of anadjacent accumulator such that when the transistor is made to conduct adata value on the data line is loaded onto the node of the dynamic latchof an adjacent accumulator, as shown in FIG. 12.

For example, FIG. 12 shows that shift circuitry 1257 can include fourshift transistors. Shift transistor 1258-1 can be arranged between dataline DIGIT(n) and node S2 of a dynamic latch of the accumulator to theleft of the compute component 1231-5. Shift transistor 1258-2 can bearranged between data line DIGIT(n) and node S1 of a dynamic latch ofthe accumulator to the left of the compute component 1231-5. Shifttransistor 1258-3 can be arranged between data line DIGIT(n−1) and nodeS1 of a dynamic latch of the compute component 1231-5. Shift transistor1258-4 can be arranged between data line DIGIT(n−1) and node S2 of adynamic latch of the compute component 1231-5. Gates of pairs of shifttransistors of the shift circuitry 1257 that are respectively coupled todata lines of a pair of complementary data lines can be commonly coupledto a SHIFT control signal that is operated to control when a shiftoccurs by causing the shift transistors to conduct.

The change in configuration and location of the shift 1257 alters theSHIFT function by the circuit illustrated in FIG. 12 (compared to theSHIFT function implemented by the circuit illustrated in FIG. 9). Thecircuit illustrated in FIG. 12 can accomplish a SHIFT right by loadingthe dynamic latch of the accumulator with data values from the senseamplifier 1206 to the left, and can accomplish a SHIFT left by loadingthe dynamic latch of the accumulator with data values from the senseamplifier 1206 to the right. With the capabilities provided by shiftcircuitry 1257, the configuration illustrated in FIG. 12 effectivelyimplements a 3-to-1 multiplexer for loading data values into the dynamiclatch of the compute component 1231-5 (e.g., to S1 and S2). Data valuescan be loaded into the dynamic latch of the compute component 1231-5from the sense amplifier 1206 to the left, from the sense amplifier 1206to the right, of from the sense amplifier 1206 associated with (i.e.,hardwired to) the particular compute component 1231-5.

According to various embodiments, the shift transistors of the shiftcircuitry 1257 can be transistors rated for a lower voltage than theisolation transistors of shift circuitry 923 shown in FIG. 9. Forexample, the isolation transistors (e.g., used for NORM and SHIFToperations) of shift circuitry 923 should be rated to switch between areference voltage (e.g., ground) and an elevated voltage (e.g., 3 V,which is elevated with respect to the supply voltage of the memoryarray). The shift transistors of the shift circuitry 1257 can be ratedto switch between a reference voltage (e.g., ground) and a supplyvoltage (e.g., V_(DD)), thus saving power by implementing the SHIFTfunction using the shift circuitry 1257 configuration provided in thecircuit illustrated in FIG. 12. The configuration illustrated in FIG. 12can also operate faster than the configuration illustrated in FIG. 9because a Row cycle is not required to accomplish the SHIFT function.

FIG. 13 is a schematic diagram illustrating sensing circuitry 1350 inaccordance with a number of embodiments of the present disclosure. Amemory cell comprises a storage element (e.g., capacitor) and an accessdevice (e.g., transistor). For instance, transistor 1302-1 and capacitor1303-1 comprises a memory cell, and transistor 1302-2 and capacitor1303-2 comprises a memory cell, etc. The cells of the memory array 1330are arranged in rows coupled by word lines 1304-X (Row X), 1304-Y (RowY), etc., and columns coupled by pairs of complementary data linesDIGIT(n−1)/DIGIT(n−1)_, DIGIT(n)/DIGIT(n)_, DIGIT(n+1)/DIGIT(n+1)_.Shift circuitry 1323 is configured to include isolation transistors1321-1 and 1321-2 coupled to a control signal 1322 (NORM) that, whenactivated, enables (e.g., turns on) the isolation transistors 1321-1 and1321-2 to couple the corresponding sense amplifier 1306 and computecomponent 1331 to a corresponding column of memory cells (e.g., to acorresponding pair of complementary data lines 1305-1 (D) and 1305-2(D_)). Shift circuitry 1323 is further configured to include isolationtransistors 1321-3 and 1321-4 coupled to a complementary control signal1319 (SHIFT) that, when activated (e.g., when NORM is deactivated),couples a particular sense amplifier 1306 and compute component 1331 toa different pair of complementary data lines (e.g., a pair ofcomplementary data lines different than the pair of complementary datalines to which isolation transistors 1321-1 and 1321-2 couple theparticular sense amplifier 1306 and compute component 1331).

The circuit illustrated in FIG. 13 is similar to the circuit illustratedin FIG. 9 but with an alternative compute component 1331-6 configurationincluding a cross-coupled latch. The dynamic latch and/or static latchof the compute component 1331-6 can be collectively referred to hereinas a secondary latch, which can serve as an accumulator. As such, thecompute component 1331-6 can operate as and/or be referred to herein asan accumulator. Data line D 1305-1 (e.g., on a sensing circuitry 1350side of the shift circuitry 1323 which can correspond to shift circuitry923 in FIG. 9) can correspond to data line D 905-1 shown in FIG. 9, dataline D_ 1305-2 (e.g., on a sensing circuitry 1350 side of the shiftcircuitry 1323) can correspond to data line D_ 905-2 shown in FIG. 9,and sense amplifier 1306 can correspond to sense amplifier 906 shown inFIG. 9. Compute component 1331-6 can correspond to compute component231-1 shown in FIG. 2.

The configuration and components of compute component 1331-6 shown inFIG. 13 is similar to the configuration and components of computecomponent 931-5 shown in FIG. 9 with the exception that a latch 1364 isadded to the S1 and S2 dynamic nodes. For example, the configuration ofcompute component 1331-6 shown in FIG. 13 shows a first input 1317-1 oflatch 1364 being directly coupled to node S2 (one source/drain region ofload/pass transistor 1318-1 is also directly coupled to node S2 as shownand described with respect to FIG. 9), and a second input 1317-2 oflatch 1364 being directly coupled to node S1 (one source/drain region ofload/pass transistor 1318-2 is also directly coupled to node S1 as shownand described with respect to FIG. 9). Compute component 1331-6 can havefeedback gain with latch 1364. As such, addition of latch 1364 canprovide additional stability to the data value stored in theaccumulator. As such, the addition of latch 1364 in compute component1331-6 can improve soft error performance over that of the sensingcircuitry illustrated in FIG. 9.

The sensing circuitry 1350 shown in FIG. 13 can be operated as thesensing circuitry illustrated in FIG. 9, in both pre-sensing (e.g.,sense amps fired before logical operation control signal active) andpost-sensing (e.g., sense amps fired after logical operation controlsignal active) modes with a result of a logical operation beinginitially stored in the sense amp. In addition, the accumulator andsense amplifier of the sensing circuitry 1350 shown in FIG. 13 can alsobe operated as described with respect to the timing diagrams illustratedin FIG. 14-17 below, with a result of the logical operation beinginitially stored in the latch of the accumulator.

The latch 1364 can be controllably enabled by coupling to an activenegative control signal line 1312-1 (GND/ACCUMB) and an active positivecontrol signal line 1312-2 (V_(DD)/ACCUM) rather than be configured tobe continuously enabled by coupling to ground and V_(DD). In variousembodiments, load/pass transistors 1308-1 and 1308-2 can each having agate coupled to one of a LOAD control signal or a PASSD/PASSDB controlsignal.

According to some embodiments, the gates of load/pass transistors 1318-1and 1318-2 can be commonly coupled to a LOAD control signal. In theconfiguration where the gates of load/pass transistors 1318-1 and 1318-2are commonly coupled to the LOAD control signal, transistors 1318-1 and1318-2 can be load transistors. As previously described (e.g., withrespect to FIG. 9), activating the LOAD control signal causes the loadtransistors to conduct, and thereby load complementary data onto nodesS1 and S2. The LOAD control signal can be elevated to a voltage greaterthan V_(DD) to pass a full V_(DD) level to S1/S2. However, elevating theLOAD control signal to a voltage greater than V_(DD) is optional, andfunctionality of the circuit shown in FIG. 13 is not contingent on theLOAD control signal being elevated to a voltage greater than V_(DD).

According to some embodiments, the gate of load/pass transistor 1318-1can be coupled to a PASSD control signal, and the gate of load/passtransistor 1318-2 can be coupled to a PASSDb control signal. In theconfiguration where the gates of load/pass transistors 1318-1 and 1318-2are respectively coupled to one of the PASSD and PASSDb control signals,transistors 1318-1 and 1318-2 can be pass transistors. Pass transistorscan be operated differently (e.g., at different times and/or underdifferent voltage/current conditions) than load transistors. As such,the configuration of pass transistors can be different than theconfiguration of load transistors.

Load transistors are constructed to handle loading associated withcoupling data lines to the local dynamic nodes S1 and S2, for example.Pass transistors are constructed to handle heavier loading associatedwith coupling data lines to an adjacent accumulator (e.g., through theshift circuitry 1323, as shown in FIG. 13). According to someembodiments, load/pass transistors 1318-1 and 1318-2 can be configuredto accommodate the heavier loading corresponding to a pass transistorbut be coupled and operated as a load transistor. Transistors 1318-1 and1318-2 configured as pass transistors can also be utilized as loadtransistors. However, transistors 1318-1 and 1318-2 configured as loadtransistors may not be capable of being utilized as pass transistors.

In a number of embodiments, the compute component 1331-6, including thelatch 1364, can comprise a number of transistors formed on pitch withthe transistors of the corresponding memory cells of an array (e.g.,array 230 shown in FIG. 2) to which they are coupled, which may conformto a particular feature size (e.g., 4F², 6F², etc.). According tovarious embodiments, latch 1364 includes four transistors 1308-1,1308-2, 1309-1, and 1309-2 coupled to a pair of complementary data linesD 1305-1 and D_ 1305-2 through load/pass transistors 1318-1 and 1318-2.However, embodiments are not limited to this configuration. The latch1364 can be a cross coupled latch (e.g., gates of a pair of transistors,such as n-channel transistors (e.g., NMOS transistors) 1309-1 and 1309-2are cross coupled with the gates of another pair of transistors, such asp-channel transistors (e.g., PMOS transistors) 1308-1 and 1308-2). Asdescribed further herein, the cross coupled latch 1364 can be referredto as a static latch.

The voltages or currents on the respective data lines D and D_ can beprovided to the respective latch inputs 1317-1 and 1317-2 of the crosscoupled latch 1364 (e.g., the input of the secondary latch). In thisexample, the latch input 1317-1 is coupled to a first source/drainregion of transistors 1308-1 and 1309-1 as well as to the gates oftransistors 1308-2 and 1309-2. Similarly, the latch input 1317-2 can becoupled to a first source/drain region of transistors 1308-2 and 1309-2as well as to the gates of transistors 1308-1 and 1309-1.

In this example, a second source/drain region of transistor 1309-1 and1309-2 is commonly coupled to an active negative control signal line1312-1 (e.g., ground (GND) or ACCUMB control signal similar to controlsignal RnIF shown in FIG. 5 with respect to the primary latch). A secondsource/drain region of transistors 1308-1 and 1308-2 is commonly coupledto an active positive control signal line 1312-2 (e.g., V_(DD) or ACCUMcontrol signal similar to control signal ACT shown in FIG. 5 withrespect to the primary latch). The active positive control signal 1312-2can provide a supply voltage (e.g., V_(DD)) and the active negativecontrol signal 1312-1 can be a reference voltage (e.g., ground) toenable the cross coupled latch 1364. According to some embodiments, thesecond source/drain region of transistors 1308-1 and 1308-2 are commonlycoupled directly to the supply voltage (e.g., V_(DD)), and the secondsource/drain region of transistor 1309-1 and 1309-2 are commonly coupleddirectly to the reference voltage (e.g., ground) so as to continuouslyenable latch 1364.

The enabled cross coupled latch 1364 operates to amplify a differentialvoltage between latch input 1317-1 (e.g., first common node) and latchinput 1317-2 (e.g., second common node) such that latch input 1317-1 isdriven to either the activated positive control signal voltage (e.g.,V_(DD)) or the activated negative control signal voltage (e.g., ground),and latch input 1317-2 is driven to the other of the activated positivecontrol signal voltage (e.g., V_(DD)) or the activated negative controlsignal voltage (e.g., ground).

One source/drain region of each of transistors 1307-1, 1307-2, 1314-1,and 1314-2 can be commonly coupled together to a reference voltagelocation 1391-1 (e.g., ground (GND)) so as to be configured as pull-downtransistors. Inverting transistors that pull-down a respective data linein performing certain logical operations, including transistor 1316-1(having a gate coupled to S2 of the dynamic latch and latch 1364) inseries with transistor 1314-1 (having a gate coupled to an ANDinvcontrol signal line 1313-1), and transistor 1316-2 (having a gatecoupled to S1 of the dynamic latch and latch 1364) in series withtransistor 1314-2 (having a gate coupled to an ANDinv control signalline 1313-2) can operate as described with respect to correspondingtransistors shown in FIG. 9 (e.g., transistor 1316-1 shown in FIG. 13corresponds to transistor 916-1 shown in FIG. 9, etc.).

FIG. 14 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure. The timing diagramshown in FIG. 14 illustrates signals (e.g., voltage signals) associatedwith performing a first operation phase of a logical operation (e.g., anR-input logical operation) using the sensing circuitry illustrated inFIG. 13. The first operation phase described with respect to FIG. 14 canbe a first operation phase of an AND, NAND, OR, or NOR operation, forinstance. Performing the operation phase illustrated in FIG. 14 caninvolve consuming significantly less energy (e.g., about half) thanprevious processing approaches that may involve providing a full swingbetween voltage rails (e.g., between a supply and ground).

In the example illustrated in FIG. 14, the voltage rails correspondingto complementary logic values (e.g., “1” and “0”) are a supply voltage(V_(DD)) and a reference voltage (e.g., ground (GND)). Prior toperforming a logical operation, an equilibration can occur such that thecomplementary data lines D and D_ are shorted together at anequilibration voltage (V_(DD)/2), as previously described.

The first operation phase of a logical operation described belowinvolves loading a first operand of the logical operation into theaccumulator. The time references (e.g., t₁, etc.) shown in FIG. 14 donot necessarily represent a same absolute or relative time as similartime references in other timing diagrams.

At time t₁, the equilibration signal 1426 is deactivated, and then aselected row is enabled (e.g., the row corresponding to a memory cellwhose data value is to be sensed and used as a first input). Signal1404-0 represents the voltage signal applied to the selected row (e.g.,Row Y 204-Y shown in FIG. 2). When row signal 1404-0 reaches thethreshold voltage (Vt) of the access transistor (e.g., 202-1 shown inFIG. 2) corresponding to the selected cell, the access transistor turnson and couples the data line D to the selected memory cell (e.g., to thecapacitor 203-1 shown in FIG. 2 if the cell is a 1T1C DRAM cell), whichcreates a differential voltage signal between the data lines D and D_(e.g., as indicated by signals 1405-1 and 1405-2 on the data lines,respectively) between times t₂ and t₃. The voltage of the selected cellis represented by signal 1403. Due to conservation of energy, creatingthe differential signal between data lines D and D_ (e.g., by couplingthe cell to data line D) does not consume energy, since the energyassociated with activating/deactivating the row signal 1404-0 can beamortized over the plurality of memory cells coupled to the row.

At time t₃, the sense amplifier (e.g., 1306 shown in FIG. 13) is enabled(e.g., a positive control signal 1431 (e.g., corresponding to ACT 590shown in FIG. 5) goes high and the negative control signal 1428 (e.g.,corresponding to RnIF 528 shown in FIG. 5) goes low), which amplifiesthe differential signal between data lines D and D_, resulting in avoltage (e.g., V_(DD)) corresponding to a logic “1” or a voltage (e.g.,ground) corresponding to a logic “0” being on data line D (and the othervoltage being on complementary data line DJ, such that the sensed datavalue is stored in the primary latch of sense amplifier 1306. Theprimary energy consumption occurs in charging the data line D (1305-1)from the equilibration voltage V_(DD)/2 to the rail voltage V_(DD). FIG.14 shows, in example, the data line voltages 1405-1 and 1405-2 thatcorrespond to a logic “1” being on data line D.

According to some embodiments, the primary latch of sense amplifier 1306can be coupled to the complementary data lines D and D_ throughrespective pass transistors (not shown in FIG. 5 but in a similarconfiguration as the manner in which latch 1364 is coupled to the datalines D and D_ through pass transistors 1318-1 and 1318-2 shown in FIG.13). The Passd control signal 1411 controls one pass transistor. ThePassdb control signal controls the other pass transistor, and here thePassdb control signal can behave here the same as the Passd controlsignal.

At time t₄, the pass transistors (if present) can be enabled (e.g., viarespective Passd and Passdb control signals 1411 applied to controllines coupled to the respective gates of the pass transistors goinghigh). At time t₅, the accumulator positive control signal 1412-1 (e.g.,Accumb) and the accumulator positive control signal 1412-2 (e.g., Accum)are activated via respective control lines 1312-1 and 1312-2 shown inFIG. 13. As described below, the accumulator control signals ACCUMB1412-1 and ACCUM 1412-2 may remain activated for subsequent operationphases. As such, in this example, activating the control signals ACCUMB1412-1 and ACCUM 1412-2 enables the secondary latch (e.g., accumulator)of compute component 1331-6 shown in FIG. 13. The sensed data valuestored in sense amplifier 1306 is transferred (e.g., copied) to thesecondary latch, including the dynamic latch and latch 1364.

At time t₆, the Passd control signal 1411 (and the Passdb controlsignal) goes low thereby turning off the pass transistors (if present).However, since the accumulator control signals ACCUMB 1412-1 and ACCUM1412-2 remain activated, an accumulated result is stored (e.g., latched)in the secondary latches (e.g., accumulator). At time t₇, the row signal1404-0 is deactivated, and the array sense amps are disabled at time t₈(e.g., sense amplifier control signals 1428 and 1431 are deactivated).

At time t₉, the data lines D and D_ are equilibrated (e.g.,equilibration signal 1426 is activated), as illustrated by data linevoltage signals 1405-1 and 1405-2 moving from their respective railvalues to the equilibration voltage (V_(DD)/2). The equilibrationconsumes little energy due to the law of conservation of energy. Asdescribed below in association with FIG. 5, equilibration can involveshorting the complementary data lines D and D_ together at anequilibration voltage, which is V_(DD)/2, in this example. Equilibrationcan occur, for instance, prior to a memory cell sensing operation.

FIGS. 15 and 16 respectively illustrate timing diagrams associated withperforming a number of logical operations using sensing circuitry inaccordance with a number of embodiments of the present disclosure.Timing diagrams shown in FIGS. 15 and 16 illustrate signals (e.g.,voltage signals) associated with performing a number of intermediateoperation phases of a logical operation (e.g., an R-input logicaloperation). For instance, timing diagram shown in FIG. 15 corresponds toa number of intermediate operation phases of an R-input NAND operationor an R-input AND operation, and timing diagram shown in FIG. 16corresponds to a number of intermediate operation phases of an R-inputNOR operation or an R-input OR operation. For example, performing an ANDor NAND operation can include performing the operation phase shown inFIG. 15 one or more times subsequent to an initial operation phase suchas that described with respect to FIG. 14. Similarly, performing an ORor NOR operation can include performing the operation phase shown anddescribed with respect to FIG. 16 one or more times subsequent to aninitial operation phase such as that described with respect to FIG. 14.

As shown in the timing diagrams illustrated in FIGS. 15 and 16, at timet₁, equilibration is deactivated (e.g., the equilibration signal1526/1626 is deactivated), and then a selected row is enabled (e.g., therow corresponding to a memory cell whose data value is to be sensed andused as an input such as a second input, third input, etc.). Signal1504-1/1604-1 represents the voltage signal applied to the selected row(e.g., Row Y 204-Y shown in FIG. 2). When row signal 1504-1 reaches thethreshold voltage (Vt) of the access transistor (e.g., 202-1 shown inFIG. 2) corresponding to the selected cell, the access transistor turnson and couples the data line D to the selected memory cell (e.g., to thecapacitor 203-1 if the cell is a 1T1C DRAM cell), which creates adifferential voltage signal between the data lines D and D_ (e.g., asindicated by signals 1505-1/1605-1 and 1505-2/1605-2, respectively)between times t₂ and t₃. The voltage of the selected cell is representedby signal 1503/1603. Due to conservation of energy, creating thedifferential signal between D and D_ (e.g., by coupling the cell to dataline D) does not consume energy, since the energy associated withactivating/deactivating the row signal 1504-1/1604-1 can be amortizedover the plurality of memory cells coupled to the row.

At time t₃, the sense amplifier (e.g., 1306 shown in FIG. 13) is enabled(e.g., a positive control signal 1590/1690, which can correspond to ACT533 shown in FIG. 5, goes high, and the negative control signal1528/1628, which can correspond to RnIF 528 shown in FIG. 5, goes low),which amplifies the differential signal between D and D_, resulting in avoltage (e.g., V_(DD)) corresponding to a logic 1 or a voltage (e.g.,ground) corresponding to a logic 0 being on data line D (and the othervoltage being on complementary data line DJ, such that the sensed datavalue is stored in the primary latch of sense amplifier 1306. Theprimary energy consumption occurs in charging the data line D (1305-1)from the equilibration voltage V_(DD)/2 to the rail voltage V_(DD).

As shown in timing diagrams illustrated in FIGS. 15 and 16, at time t₄(e.g., after the selected cell is sensed), only one of control signals1511-1 (Passd) shown in FIGS. 15 and 1611-2 (Passdb) shown in FIG. 16 isactivated (e.g., only one of pass transistors (if present) is enabled),depending on the particular logic operation. For example, since thetiming diagram illustrated in FIG. 15 corresponds to an intermediatephase of a NAND or AND operation, control signal 1511-1 (Passd) isactivated at time t₄ to turn on the pass transistor coupling the primarylatch to data line D and the Passdb control signal remains deactivatedleaving the pass transistor coupling the primary latch to data line D_turned off. Conversely, since the timing diagram illustrated in FIG. 16corresponds to an intermediate phase of a NOR or OR operation, controlsignal 1611-2 (Passdb) is activated at time t₄ to turn on the passtransistor coupling the primary latch to data line D_ and control signalPassd remains deactivated leaving the pass transistor coupling theprimary latch to data line D turned off. Recall from above that theaccumulator control signals 1412-1 (Accumb) and 1412-2 (Accum) wereactivated during the initial operation phase described with respect toFIG. 14, and they remain activated during the intermediate operationphase(s).

Since the accumulator was previously enabled, activating only Passd(1511-1 as shown in FIG. 15) results in accumulating the data valuecorresponding to the voltage signal 1505-1 shown in FIG. 15corresponding to data line D. Similarly, activating only Passdb (1611-2as shown in FIG. 16) results in accumulating the data valuecorresponding to the voltage signal 1605-2 corresponding to data lineD_. For instance, in an example AND/NAND operation shown in the timingdiagram illustrated in FIG. 15 in which only Passd (1511-1) isactivated, if the data value stored in the second selected memory cellis a logic “0,” then the accumulated value associated with the secondarylatch is asserted low such that the secondary latch stores logic “0.” Ifthe data value stored in the second selected memory cell is not alogic“0,” then the secondary latch retains its stored first selectedmemory cell data value (e.g., a logic “1” or a logic “0”). As such, inthis AND/NAND operation example, the secondary latch is serving as azeroes (0s) accumulator.

Similarly, in an example OR/NOR operation shown in the timing diagramillustrated in FIG. 16 in which only Passdb 1611-2 is activated, if thedata value stored in the second selected memory cell is a logic “1,”then the accumulated value associated with the secondary latch isasserted high such that the secondary latch stores logic “1.” If thedata value stored in the second selected memory cell is not a logic “1,”then the secondary latch retains its stored first selected memory celldata value (e.g., a logic “1” or a logic “0”). As such, in this OR/NORoperation example, the secondary latch is effectively serving as a ones(1s) accumulator since voltage signal 1605-2 on D_ is setting the truedata value of the accumulator.

At the conclusion of an intermediate operation phase such as that shownin FIG. 15 or 16, the Passd signal 1511-1 (e.g., for AND/NAND) or thePassdb signal 1611-2 (e.g., for OR/NOR) is deactivated (e.g., at timet₅), the selected row is disabled (e.g., at time t₆), the senseamplifier is disabled (e.g., at time t₇), and equilibration occurs(e.g., at time t₈). An intermediate operation phase such as thatillustrated in FIG. 15 or 16 can be repeated in order to accumulateresults from a number of additional rows. As an example, the sequence oftiming diagram illustrated in FIGS. 15 and/or 16 can be performed asubsequent (e.g., second) time for a third memory cell, a subsequent(e.g., third) time for a fourth memory cell, etc. For instance, for a10-input NOR operation, the intermediate phase shown in FIG. 16 canoccur 9 times to provide 9 inputs of the 10-input logical operation,with the tenth input being determined during the initial operation phase(e.g., as described with respect to FIG. 14).

FIG. 17 illustrates a timing diagram associated with performing a numberof logical operations using sensing circuitry in accordance with anumber of embodiments of the present disclosure. The timing diagramillustrated in FIG. 17 shows signals (e.g., voltage signals) associatedwith performing a last operation phase of a logical operation (e.g., anR-input logical operation). For instance, the timing diagram illustratedin FIG. 17 corresponds to a last operation phase of an R-input ANDoperation or an R-input OR operation.

For example, performing a last operation phase of an R-input can includeperforming the operation phase shown in FIG. 17 subsequent to a numberof iterations of the intermediate operation phase(s) described inassociation with FIGS. 15 and/or 16. Table 3 shown below indicates theFigures corresponding to the sequence of operation phases associatedwith performing a number of R-input logical operations in accordancewith a number of embodiments described herein.

TABLE 3 Operation FIG. 14 FIG. 15 FIG. 16 FIG. 17 AND First phase R-1Last phase iterations NAND First phase R-1 iterations OR First phase R-1Last phase iterations NOR First phase R-1 iterations

A NAND operation can be implemented, for example, by storing the resultof the R−1 iterations for an AND operation in the sense amplifier, theninverting the sense amplifier before conducting the last operation phaseto store the result (described below). A NOR operation can beimplemented, for example, by storing the result of the R−1 iterationsfor an OR operation in the sense amplifier, then inverting the senseamplifier before conducting the last operation phase to store the result(described below).

The last operation phase illustrated in the timing diagram of FIG. 17 isdescribed in association with storing a result of an R-input logicaloperation to a row of the array (e.g., array 230 shown in FIG. 2).However, as described above, in a number of embodiments, the result canbe stored to a suitable location other than back to the array (e.g., toan external register associated with a controller and/or host processor,to a memory array of a different memory device, etc., via I/O lines).

As shown in timing diagram illustrated in FIG. 17, at time equilibrationis deactivated (e.g., the equilibration signal 1726 is deactivated) suchthat data lines D and D_ are floating. At time t₂, the Passd controlsignal 1711 (and Passdb signal) is activated for an AND or OR operation.

Activating the Passd control signal 1711 (and Passdb signal) (e.g., inassociation with an AND or OR operation) transfers the accumulatedoutput stored in the secondary latch of compute component 1331-6 shownin FIG. 13 to the primary latch of sense amplifier 1306. For instance,for an AND operation, if any of the memory cells sensed in the prioroperation phases (e.g., the first operation phase illustrated in FIG. 14and one or more iterations of the intermediate operation phaseillustrated in FIG. 15) stored a logic “0” (e.g., if any of the R-inputsof the AND operation were a logic “0”), then the data line D_ will carrya voltage corresponding to logic “1” (e.g., V_(DD)) and data line D willcarry a voltage corresponding to logic “0” (e.g., ground). For this ANDoperation example, if all of the memory cells sensed in the prioroperation phases stored a logic “1” (e.g., all of the R-inputs of theAND operation were logic “1”), then the data line D_ will carry avoltage corresponding to logic “0” and data line D will carry a voltagecorresponding to logic “1”. At time t₃, the primary latch of senseamplifier 1306 is then enabled (e.g., a positive control signal 1731(e.g., corresponding to ACT 590 shown in FIG. 5) goes high and thenegative control signal 1728 (e.g., corresponding to RnIF 528 shown inFIG. 5) goes low), which amplifies the differential signal between datalines D and D_ such that the data line D now carries the ANDed result ofthe respective input data values as determined from the memory cellssensed during the prior operation phases. As such, data line D will beat ground if any of the input data values are a logic “0” and data lineD will be at V_(DD) if all of the input data values are a logic “1.”

For an OR operation, if any of the memory cells sensed in the prioroperation phases (e.g., the first operation phase of FIG. 14 and one ormore iterations of the intermediate operation phase shown in FIG. 16)stored a logic “1” (e.g., if any of the R-inputs of the OR operationwere a logic “1”), then the data line D_ will carry a voltagecorresponding to logic “0” (e.g., ground) and data line D will carry avoltage corresponding to logic “1” (e.g., V_(DD)). For this OR example,if all of the memory cells sensed in the prior operation phases stored alogic “0” (e.g., all of the R-inputs of the OR operation were logic“0”), then the data line D will carry a voltage corresponding to logic“0” and data line D_ will carry a voltage corresponding to logic “1.” Attime t₃, the primary latch of sense amplifier 1306 is then enabled andthe data line D now carries the ORed result of the respective input datavalues as determined from the memory cells sensed during the prioroperation phases. As such, data line D will be at V_(DD) if any of theinput data values are a logic “1” and data line D will be at ground ifall of the input data values are a logic “0.”

The result of the R-input AND or OR logical operations can then bestored back to a memory cell of array 230 shown in FIG. 2. In theexamples shown in FIG. 17, the result of the R-input logical operationis stored to a memory cell coupled to the last row opened (e.g., row ofthe last logical operation operand). Storing the result of the logicaloperation to a memory cell simply involves enabling the associated rowaccess transistor by enabling the particular row. The capacitor of thememory cell will be driven to a voltage corresponding to the data valueon the data line D (e.g., logic “1” or logic “0”), which essentiallyoverwrites whatever data value was previously stored in the selectedmemory cell. It is noted that the selected memory cell can be a samememory cell that stored a data value used as an input for the logicaloperation. For instance, the result of the logical operation can bestored back to a memory cell that stored an operand of the logicaloperation.

The timing diagram illustrated in FIG. 17 show, at time t₃, the positivecontrol signal 1731 and the negative control signal 1728 beingdeactivated (e.g., signal 1731 goes high and signal 1728 goes low) todeactivate the sense amplifier 1306 shown in FIG. 13. At time t₄ thePassd control signal 1711 (and Passdb signal) that was activated at timet₂ is deactivated. Embodiments are not limited to this example. Forinstance, in a number of embodiments, the sense amplifier 1306 shown inFIG. 13 may be enabled subsequent to time t₄ (e.g., after he Passdcontrol signal 1711 (and Passdb signal) are deactivated).

As shown in FIG. 17, at time t₅, a selected row is enabled (e.g., by rowenabling signal 1704 going high, which drives the capacitor of theselected cell to the voltage corresponding to the logic value stored inthe accumulator. At time t₆ the selected row is disabled. At time t₇ thesense amplifier 1306 shown in FIG. 13 is disabled (e.g., positivecontrol signal 1728 and negative control signal 1731 are deactivated),and at time t₈ equilibration occurs (e.g., signal 1726 is activated andthe voltages on the complementary data lines 1705-1 (D) and 1705-2 (D_)are brought to the equilibration voltage).

Although the example of performing a last operation phase of an R-inputwas discussed above with respect to FIG. 17 for performing AND and ORlogical operations, embodiments are not limited to these logicaloperations. For example, the NAND and NOR operations can also involve alast operation phase of an R-input that is stored back to a memory cellof array 230 using control signals to operate the sensing circuitryillustrated in FIG. 13.

FIG. 18 is a schematic diagram illustrating sensing circuitry inaccordance with a number of embodiments of the present disclosure. Thecircuit illustrated in FIG. 18 is similar to the circuit illustrated inFIG. 13 but with an alternative configuration having a modified shiftimplementation, as explicitly shown in FIG. 18 (and described below).The circuit shown in FIG. 18 can include a similar or differentembodiment of the configuration of the compute component 1831-7 as thatshown and described with respect to compute component 1331-6 shown inFIG. 13.

According to various embodiments of the present disclosure, theconfiguration of the compute component 1831-7 is the same as thatprovided with respect to compute component 1331-6 in FIG. 13. Inparticular, the compute component 1831-7 can include load/passtransistors 1818-1 and 1818-2, each having a gate coupled to one of aLOAD control signal or a PASSD/PASSDB control signal. As previouslydescribed (e.g., with respect to FIG. 9), activating the LOAD controlsignal causes the load transistors to conduct, and thereby loadcomplementary data onto nodes S1 and S2. The LOAD control signal can beelevated to a voltage greater than V_(DD) to pass a full V_(DD) level toS1/S2. However, elevating the LOAD control signal to a voltage greaterthan V_(DD) is optional, and functionality of the circuit shown in FIG.9 is not contingent on the LOAD control signal being elevated to avoltage greater than V_(DD).

As described with respect to FIG. 13, the compute component 1831-7 canalternatively have a transistor 1818-1 having a gate coupled to a PASSDcontrol signal, and the compute component 1831-7 can have a transistor1818-2 having a gate coupled to a PASSDb control signal. In theconfiguration where the gates of transistors 1818-1 and 1818-2 arerespectively coupled to one of the PASSD and PASSDb control signals,transistors 1818-1 and 1818-2 can be pass transistors. Pass transistorscan be operated differently (e.g., at different times and/or underdifferent voltage/current conditions) than load transistors. As such,the configuration of pass transistors can be different than theconfiguration of load transistors. Load transistors are constructed tohandle loading associated with coupling data lines to the local dynamicnodes S1 and S2, for example. Pass transistors are constructed to handleloading associated with coupling data lines to an adjacent accumulator(e.g., through the shift circuitry 1868-1, as shown in FIG. 18).

Additionally, the circuit shown in FIG. 18 does not include a shiftcircuitry corresponding to shift circuitry 1323 shown in FIG. 13. Thecircuit shown in FIG. 18 does include shift circuitry (e.g., 1868-1,1868-2) comprising one pair of isolation transistors. The shiftcircuitry 1868-1 and 1868-2 can each include a single pair of shifttransistors (e.g., 1869-1 and 1869-2, 1869-3 and 1869-4).

The circuit illustrated in FIG. 18 accomplishes a SHIFT function byusing the latch of the accumulator and the latch of the sense amplifierin a master-slave configuration. According to embodiments of the presentdisclosure, SHIFT operations (right or left) do not pre-copy the Row Xdata value into the accumulator. Operations to shift right a Row X datavalue can be summarized as follows:

Activate (e.g., Activate) Shift

-   -   Sense amplifier data is written into the accumulator one to the        right.

Deactivate (e.g., Deactivate) Shift

Equilibrate (EQ) data lines

Deactivate EQ

Activate Passd and Passdb

Fire Sense Amps (after which shifted data resides in the sense amps)

Deactivate Passd and Passdb

The “Activate Shift” shown in the pseudo code above indicates that theSHIFT control signal goes high, which causes the shift transistors(e.g., 1869-1 and 1869-2, 1869-3 and 1869-4) to conduct to couple anadjacent pair of complementary data lines to the dynamic latch (andcross-coupled latch) of the accumulator and the sense amplifier 1806.The pair of complementary data lines corresponding to the computecomponent 1831-7 (e.g., D 1805-1 and D_ 1805-2) are isolated fromcompute component 1831-7 because transistors 1818-1 and 1818-2 are notconducting.

After the shifted right Row X data value from the left adjacent pair ofcomplementary data lines is stored in the latches of compute component1831-7, the “Deactivate Shift” shown in the pseudo code above indicatesthat the SHIFT control signal goes low, which causes the shifttransistors (e.g., 1869-1 and 1869-2, 1869-3 and 1869-4) to stopconducting and isolate the left adjacent pair of complementary datalines from compute component 1831-7.

Once the left adjacent pair of complementary data lines from computecomponent 1831-7, the “Equilibrate (EQ) data lines” shown in the pseudocode above indicates that the pairs of complementary data lines can beequilibrated in a same manner as described previously for “Precharge”pseudo code operations. After equilibrating the pairs of complementarydata lines, the “Deactivate EQ” shown in the pseudo code above indicatesthat the equilibration signal corresponding to the sense amplifier 1806is disabled (e.g., such that the complementary data lines D 1805-1 andD_ 1805-2 are no longer shorted to V_(DD)/2), as described previously.

After equilibration is complete, the data value stored in the dynamiclatch (and cross-coupled latch) of the accumulator can be copied to thesense amplifier 1806. The “Activate Passd and Passdb” shown in thepseudo code above indicates that the PASSD and PASSDb control signals gohigh, which causes transistors 1818-1 and 1818-2 to conduct, whichcouples the dynamic latch (and cross-coupled latch) of the accumulatorto the pair of complementary data lines D 1805-1 and D_ 1805-2. Thisplaces the data value stored in the dynamic latch (and cross-coupledlatch) of the accumulator on the pair of complementary data lines D1805-1 and D_ 1805-2. Thereafter, the “Fire Sense Amps” shown in thepseudo code above indicates that the data value on the pair ofcomplementary data lines D 1805-1 and D_ 1805-2 is stored in the senseamplifier 1806, as previously described. Once the data value is storedin the sense amplifier 1806, the “Deactivate Passd and Passdb” shown inthe pseudo code above indicates that the PASSD and PASSDb controlsignals go low, which causes transistors 1818-1 and 1818-2 to stopconducting and isolates the dynamic latch (and cross-coupled latch) ofthe accumulator from the pair of complementary data lines D 1805-1 andD_ 1805-2 and the sense amplifier 1806.

Operations to shift left a Row X data value can be summarized asfollows:

Activate Passd and Passdb

-   -   Sense amplifier data is written into the accumulator

Deactivate Passd and Passdb

Equilibrate (EQ) data lines

Deactivate EQ

Activate (e.g., Activate) Shift

Fire Sense Amps (after which shifted data resides in the sense amps)

Deactivate (e.g., Deactivate) Shift

The “Activate Passd and Passdb” shown in the pseudo code above indicatesthat the PASSD and PASSDb control signals go high, which causestransistors 1818-1 and 1818-2 to conduct, thereby coupling the dynamiclatch (and cross-coupled latch) of the accumulator to the pair ofcomplementary data lines D 1805-1 and D_ 1805-2 (having the Row X datavalue thereon). This operation places the Row X data value in thedynamic latch (and cross-coupled latch) of the accumulator from the pairof complementary data lines D 1805-1 and D_ 1805-2.

After the Row X data value is stored in the latch (and cross-coupledlatch) of the accumulator, the “Equilibrate (EQ) data lines” shown inthe pseudo code above indicates that the pairs of complementary datalines can be equilibrated in a same manner as described previously for“Precharge” pseudo code operations. After equilibrating the pairs ofcomplementary data lines, the “Deactivate EQ” shown in the pseudo codeabove indicates that the equilibration signal corresponding to the senseamplifier 1806 is disabled (e.g., such that the complementary data linesD 1805-1 and D_ 1805-2 are no longer shorted to V_(DD)/2), as describedpreviously.

After equilibration is complete, the “Activate Shift” shown in thepseudo code above indicates that the SHIFT control signal goes high,which causes the shift transistors (e.g., 1869-1 and 1869-2, 1869-3 and1869-4) to conduct coupling a right adjacent pair of complementary datalines to the dynamic latch (and cross-coupled latch) of the accumulatorand the sense amplifier 1806. The pair of complementary data linescorresponding to the compute component 1831-7 (e.g., D 1805-1 and D_1805-2) are isolated from compute component 1831-7 because transistors1818-1 and 1818-2 are not conducting.

Once the dynamic latch (and cross-coupled latch) of the accumulator arecoupled to the right adjacent pair of complementary data lines, the“Fire Sense Amps” shown in the pseudo code above indicates that the datavalue on the right adjacent pair of complementary data lines is storedin the sense amplifier 1806, in a manner previously described forstoring a data value in a sense amp.

After the shifted left Row X data value from the right adjacent pair ofcomplementary data lines is stored in the sense amplifier 1806, the“Deactivate Shift” shown in the pseudo code above indicates that theSHIFT control signal goes low, which causes the shift transistors (e.g.,1869-1 and 1869-2, 1869-3 and 1869-4) to stop conducting and isolate theright adjacent pair of complementary data lines from compute component1831-7.

After the shifted left Row X data value from the right adjacent pair ofcomplementary data lines is stored in the sense amplifier 1806, the“Deactivate Shift” shown in the pseudo code above indicates that theSHIFT control signal goes low, which causes the shift transistors (e.g.,1869-1 and 1869-2, 1869-3 and 1869-4) to stop conducting and isolate theright adjacent pair of complementary data lines from compute component1831-7 and sense amplifier 1806.

The above-described shift cycle is faster than previously-describedshift cycles since a Row cycle can be eliminated. Power can be reducedbecause a Row is not opened; thus, there is no associated charging anddischarging of the memory cells. Power can also be reduced from thecircuit configuration shown in FIG. 13 with a shift circuitry 1323because an elevated voltage (e.g., 3.0 V) is applied to the isolationtransistors of the shift circuitry (e.g., 221-1, 221-2, 221-3, 221-4shown in FIG. 2), whereas V_(DD) (e.g., 1.2 V) is utilized inimplementing SHIFT functionality using the circuit illustrated in FIG.18.

While example embodiments including various combinations andconfigurations of sensing circuitry, sense amps, compute component,dynamic latches, isolation devices, and/or shift circuitry have beenillustrated and described herein, embodiments of the present disclosureare not limited to those combinations explicitly recited herein. Othercombinations and configurations of the sensing circuitry, sense amps,compute component, dynamic latches, isolation devices, and/or shiftcircuitry disclosed herein are expressly included within the scope ofthis disclosure.

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art will appreciate that anarrangement calculated to achieve the same results can be substitutedfor the specific embodiments shown. This disclosure is intended to coveradaptations or variations of one or more embodiments of the presentdisclosure. It is to be understood that the above description has beenmade in an illustrative fashion, and not a restrictive one. Combinationof the above embodiments, and other embodiments not specificallydescribed herein will be apparent to those of skill in the art uponreviewing the above description. The scope of the one or moreembodiments of the present disclosure includes other applications inwhich the above structures and methods are used. Therefore, the scope ofone or more embodiments of the present disclosure should be determinedwith reference to the appended claims, along with the full range ofequivalents to which such claims are entitled.

In the foregoing Detailed Description, some features are groupedtogether in a single embodiment for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the disclosed embodiments of the presentdisclosure have to use more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thus,the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment.

What is claimed is:
 1. A memory device, comprising: an array of memorycells coupled to sensing circuitry; and control circuitry configured tooperate the array and sensing circuitry to perform logical operations;wherein the sensing circuitry comprises: a sense amplifier coupled to apair of complementary sense lines corresponding to a column of thearray; and a compute component coupled to the sense amplifier andcomprising a dynamic latch; and wherein the control circuitry isconfigured to: activate a selected logical operation control signalcorresponding to a selected logical operation; wherein activation of theselected logical operation control signal causes a result of theselected logical operation between a data value residing in the dynamiclatch and a data value residing in a latch of the sense amplifier to bestored initially in the latch of the sense amplifier by overwriting thedata value residing in the latch of the sense amplifier or leaving thedata value residing in the latch of the sense amplifier unchangeddepending on the selected logical operation; and wherein the computecomponent comprises: a first source/drain region of a first transistorcoupled to a first one of the pair of complementary sense lines anddirectly coupled to a first source/drain region of a first loadtransistor; and a first source/drain region of a second transistorcoupled to a second one of the pair of complementary sense lines anddirectly coupled to a first source/drain region of a second loadtransistor; and wherein, prior to activating the selected logicaloperation control signal, the load transistor is enabled to transfer adata value residing in the latch of the sense amplifier to the dynamiclatch.
 2. The memory device of claim 1, wherein the compute component isformed on pitch with memory cells of the array.
 3. The memory device ofclaim 1, wherein the control circuitry is configured to perform theselected logical operation without transferring data values from thedynamic latch to a host coupled to the memory device.
 4. The memorydevice of claim 3, wherein the control circuitry is configured toperform the selected logical operation without transferring data valuesfrom the latch of the sense amplifier to the host.
 5. The memory deviceof claim 1, wherein the control circuitry is configured to perform theselected logical operation without transferring data values from thelatch of the sense amplifier or from the dynamic latch to the controlcircuitry.
 6. The memory device of claim 1, wherein the computecomponent further comprises a static latch coupled to the dynamic latch.7. The memory device of claim 1, wherein the dynamic latch of thecompute component is the only latch of the compute component.
 8. Thememory device of claim 7, wherein the latch of the sense amplifier isthe only latch of the sense amplifier.
 9. The memory device of claim 8,wherein: prior to activating the selected logical operation controlsignal, the data value residing in the dynamic latch corresponds to afirst input of the selected logical operation and the data valueresiding in the latch of the sense amplifier corresponds to a secondinput of the selected logical operation; and subsequent to activatingthe selected logical operation control signal, the result of theselected logical operation resides in the latch of the sense amplifier.10. A memory device, comprising: an array of memory cells coupled tosensing circuitry; and control circuitry configured to operate the arrayand sensing circuitry to perform logical operations; wherein the sensingcircuitry comprises: a sense amplifier coupled to a pair ofcomplementary sense lines corresponding to a column of the array; and acompute component coupled to the sense amplifier and comprising adynamic latch; and wherein the control circuitry is configured to:activate a selected logical operation control signal corresponding to aselected logical operation; wherein activation of the selected logicaloperation control signal causes a result of the selected logicaloperation between a data value residing in the dynamic latch and a datavalue residing in a latch of the sense amplifier to be stored initiallyin the latch of the sense amplifier by overwriting the data valueresiding in the latch of the sense amplifier or leaving the data valueresiding in the latch of the sense amplifier unchanged depending on theselected logical operation; and wherein the compute component comprises:a first source/drain region of a first transistor coupled to a first oneof the pair of complementary sense lines and to a first source/drainregion of a first load transistor; a first source/drain region of asecond transistor coupled to a second one of the pair of complementarysense lines and to a first source/drain region of a second loadtransistor; a second source/drain region of the first transistor coupledto a first source/drain region of a first dynamic latch transistor; anda second source/drain region of the second transistor coupled to a firstsource/drain region of a second dynamic latch transistor.
 11. The memorydevice of claim 10, wherein the dynamic latch of the compute componentis the only latch of the compute component.
 12. The memory device ofclaim 10, wherein the compute component further comprises a static latchcoupled to the dynamic latch.
 13. The memory device of claim 10, whereinthe selected logical operation control signal is one of a plurality oflogical operation control signals including at least a first controlsignal activated to perform a logical AND operation and a second controlsignal activated to perform a logical OR operation.
 14. The memorydevice of claim 10, wherein the compute component serves as anaccumulator.
 15. The memory device of claim 10, wherein the computecomponent further comprises: a first invert transistor coupled to thefirst dynamic latch transistor; and a second invert transistor coupledto the second dynamic latch transistor.
 16. The memory device of claim15, wherein the first invert transistor and the second invert transistorare each coupled to the first load transistor and to the second loadtransistor.
 17. A memory device, comprising: an array of memory cellscoupled to sensing circuitry; and control circuitry configured tooperate the array and sensing circuitry to perform logical operations;wherein the sensing circuitry comprises: a sense amplifier coupled to apair of complementary sense lines corresponding to a column of thearray; and a compute component coupled to the sense amplifier andcomprising a dynamic latch; and wherein the control circuitry isconfigured to: activate a selected logical operation control signalcorresponding to a selected logical operation; wherein activation of theselected logical operation control signal causes a result of theselected logical operation between a data value residing in the dynamiclatch and a data value residing in a latch of the sense amplifier to bestored initially in the latch of the sense amplifier by overwriting thedata value residing in the latch of the sense amplifier or leaving thedata value residing in the latch of the sense amplifier unchangeddepending on the selected logical operation; and wherein the computecomponent comprises: a source/drain region of a first dynamic latchtransistor coupled to a first one of the pair of complementary senselines; a source/drain region of a second dynamic latch transistorcoupled to a second one of the pair of complementary sense lines; a gateof the first dynamic latch transistor coupled to a source/drain regionof a load transistor; a gate of the second dynamic latch transistorcoupled to a source/drain region of a different load transistor; and agate of the first load transistor coupled to a gate of the differentload transistor.
 18. The memory device of claim 17, wherein the computecomponent further comprises: a first pull-down transistor having a firstsource/drain region coupled to the first dynamic latch transistor; and asecond pull-down transistor having a first source/drain region coupledto the second dynamic latch transistor.
 19. The memory device of claim18, wherein the compute component further comprises: a third pull-downtransistor having a first source/drain region coupled to a secondsource/drain region of the first pull-down transistor; and a fourthpull-down transistor having a first source/drain region coupled to asecond source/drain region of the second pull-down transistor.
 20. Thememory device of claim 18, wherein the second source/drain region of thefirst pull-down transistor is coupled to the second source/drain regionof the second pull-down transistor.